Although we can't necessarily see electricity, we can measure it by its effects. An ampere, or amp, represents the amount of current in a circuit. Voltage is defined scientifically as the circuit's "potential difference," and can be seen as the amount of "pressure" that drives electricity in a circuit. Watts are a measure of the use of electrical power, and one watt is equal to one volt multiplied by one amp.

In this case it is helpful to use an analogy to help us understand how each of these terms relate to each other. One commonly used analogy is that of the garden hose. The water pressure in the hose is like the voltage, and the amp value is like the volume of water flowing through the hose. The wattage, then, is the total amount of water that comes out of the hose, per unit of time.

If we replace the hose in the above analogy with an electrical wire, it is simple to see how they relate. In an electrical circuit, the voltage may be 220, as it is in most electrical outlets in all the world except the United States and other few countries. Most appliances are meant to run on this voltage, although each operates at different amp levels, and therefore at a different wattage.

An appliance which uses a large amount of current, such as an electric stove, may be on a separate circuit with a higher voltage. There must be more pressure -- or voltage -- to supply the needed amps to the appliance, because it has a higher wattage. In other words, it uses up more current, or amps, per unit of time, than another appliance. Without the higher voltage, it wouldn't run, because it would be "starved" for the amps it needed to be able to operate.

Another electrical term that helps tie together the other three is the ohm, which is a unit of electrical resistance. Going back to the garden hose analogy, if the hose has a larger diameter, more water will be able to flow through. A circuit with a high resistance value, expressed in ohms, is able to carry fewer amps than one with lower resistance, regardless of the voltage. If a high voltage encounters high resistance, the amount of possible amps in the circuit will be very low -- not much water will get through a narrow hose, no matter how high the pressure is.

Electrical consumption is measured in watts, or watt-hours, and this is the basis on which a power company bills a customer for electrical usage. For convenience, power companies measure consumption in a unit called a kilowatt-hour, which is the equivalent of using 1000 watts of power for one hour. The average household uses hundreds of kilowatt-hours per month.

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A multi-core processor is a processing system composed of two or more independent cores (or CPUs). The cores are typically integrated onto a single integrated circuit die (known as a chip multiprocessor or CMP), or they may be integrated onto multiple dies in a single chip package. A many-core processor is one in which the number of cores is large enough that traditional multi-processor techniques are no longer efficient — this threshold is somewhere in the range of several tens of cores — and likely requires a network on chip.

A dual-core processor contains two cores, and a quad-core processor contains four cores. A multi-core processor implements multiprocessing in a single physical package. Cores in a multi-core device may be coupled together tightly or loosely. For example, cores may or may not share caches, and they may implement message passing or shared memory inter-core communication methods. Common network topologies to interconnect cores include: bus, ring, 2-dimensional mesh, and crossbar. All cores are identical in homogeneous multi-core systems and they are not identical in heterogeneous multi-core systems. Just as with single-processor systems, cores in multi-core systems may implement architectures such as superscalar, VLIW, vector processing, SIMD, or multithreading.

Multi-core processors are widely used across many application domains including: general-purpose, embedded, network, digital signal processing, and graphics.

The amount of performance gained by the use of a multi-core processor is strongly dependent on the software algorithms and implementation. In particular, the possible gains are limited by the fraction of the software that can be "parallelized" to run on multiple cores simultaneously; this effect is described by Amdahl's law. In the best case, so-called embarrassingly parallel problems may realize speedup factors near the number of cores. Many typical applications, however, do not realize such large speedup factors and thus, the parallelization of software is a significant on-going topic of research.

Advantages

The proximity of multiple CPU cores on the same die allows the cache coherency circuitry to operate at a much higher clock rate than is possible if the signals have to travel off-chip. Combining equivalent CPUs on a single die significantly improves the performance of cache snoop (alternative: Bus snooping) operations. Put simply, this means that signals between different CPUs travel shorter distances, and therefore those signals degrade less. These higher quality signals allow more data to be sent in a given time period since individual signals can be shorter and do not need to be repeated as often.

The largest boost in performance will likely be noticed in improved response time while running CPU-intensive processes, like antivirus scans, ripping/burning media (requiring file conversion), or searching for folders. For example, if the automatic virus scan initiates while a movie is being watched, the application running the movie is far less likely to be starved of processor power, as the antivirus program will be assigned to a different processor core than the one running the movie playback.

Assuming that the die can fit into the package, physically, the multi-core CPU designs require much less Printed Circuit Board (PCB) space than multi-chip SMP designs. Also, a dual-core processor uses slightly less power than two coupled single-core processors, principally because of the decreased power required to drive signals external to the chip. Furthermore, the cores share some circuitry, like the L2 cache and the interface to the front side bus (FSB). In terms of competing technologies for the available silicon die area, multi-core design can make use of proven CPU core library designs and produce a product with lower risk of design error than devising a new wider core design. Also, adding more cache suffers from diminishing returns.

Disadvantages

In addition to operating system (OS) support, adjustments to existing software are required to maximize utilization of the computing resources provided by multi-core processors. Also, the ability of multi-core processors to increase application performance depends on the use of multiple threads within applications. The situation is improving: for example the Valve Corporation's Source engine, offers multi-core support, and Crytek has developed similar technologies for CryEngine 2, which powers their game, Crysis. Emergent Game Technologies' Gamebryo engine includes their Floodgate technology[3] which simplifies multicore development across game platforms. See Dynamic Acceleration Technology for the Santa Rosa platform for an example of a technique to improve single-thread performance on dual-core processors.

Integration of a multi-core chip drives production yields down and they are more difficult to manage thermally than lower-density single-chip designs. Intel has partially countered this first problem by creating its quad-core designs by combining two dual-core on a single die with a unified cache, hence any two working dual-core dies can be used, as opposed to producing four cores on a single die and requiring all four to work to produce a quad-core. From an architectural point of view, ultimately, single CPU designs may make better use of the silicon surface area than multiprocessing cores, so a development commitment to this architecture may carry the risk of obsolescence. Finally, raw processing power is not the only constraint on system performance. Two processing cores sharing the same system bus and memory bandwidth limits the real-world performance advantage. If a single core is close to being memory bandwidth limited, going to dual-core might only give 30% to 70% improvement. If memory bandwidth is not a problem, a 90% improvement can be expected. It would be possible for an application that used two CPUs to end up running faster on one dual-core if communication between the CPUs was the limiting factor, which would count as more than 100% improvement.

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Power line communication or power line carrier (PLC), also known as Power line Digital Subscriber Line (PDSL), mains communication, power line telecom (PLT), or power line networking (PLN), is a system for carrying data on a conductor also used for electric power transmission. Broadband over Power Lines (BPL) uses PLC by sending and receiving information bearing signals over power lines to provide access to the Internet.

Electrical power is transmitted over high voltage transmission lines, distributed over medium voltage, and used inside buildings at lower voltages. Powerline communications can be applied at each stage. Most PLC technologies limit themselves to one set of wires (for example, premises wiring), but some can cross between two levels (for example, both the distribution network and premises wiring).

All power line communications systems operate by impressing a modulated carrier signal on the wiring system. Different types of powerline communications use different frequency bands, depending on the signal transmission characteristics of the power wiring used. Since the power wiring system was originally intended for transmission of AC power, the power wire circuits have only a limited ability to carry higher frequencies. The propagation problem is a limiting factor for each type of power line communications.

Data rates over a power line communication system vary widely. Low-frequency (about 100-200 kHz) carriers impressed on high-voltage transmission lines may carry one or two analog voice circuits, or telemetry and control circuits with an equivalent data rate of a few hundred bits per second; however, these circuits may be many miles (kilometres) long. Higher data rates generally imply shorter ranges; a local area network operating at millions of bits per second may only cover one floor of an office building, but eliminates installation of dedicated network cabling.

Internet access (broadband over powerlines)
Broadband over power lines (BPL), also known as power-line Internet or powerband, is the use of PLC technology to provide broadband Internet access through ordinary power lines. A computer (or any other device) would need only to plug a BPL "modem" into any outlet in an equipped building to have high-speed Internet access. International Broadband Electric Communications or IBEC and other companies currently offer BPL service to several electric cooperatives.

BPL may offer benefits over regular cable or DSL connections: the extensive infrastructure already available appears to allow people in remote locations to access the Internet with relatively little equipment investment by the utility. Also, such ubiquitous availability would make it much easier for other electronics, such as televisions or sound systems, to hook up.

Home control (narrowband)
Power line communications technology can use the household electrical power wiring as a transmission medium. INSTEON and X10 are the two most popular,de facto standards using power line communications for home control. This is a technique used in home automation for remote control of lighting and appliances without installation of additional control wiring.

Home networking (broadband)
Power line communications can also be used to interconnect home computers, peripherals or other networked consumer peripherals. Proprietary specifications for power line home networking have been developed by a number of different companies within the framework of the HomePlug Powerline Alliance, the Universal Powerline Association and the HD-PLC Alliance.

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DSL or xDSL, is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop, although in recent years, the term digital subscriber line has been widely adopted as a more marketing-friendly term for ADSL, which is the most popular version of consumer-ready DSL. DSL can be used at the same time and on the same telephone line with regular telephone, as it uses high frequency, while regular telephone uses low frequency.

Typically, the download speed of consumer DSL services ranges from 256 kilobits per second (kbit/s) to 24,000 kbit/s, depending on DSL technology, line conditions and service level implemented. Typically, upload speed is lower than download

DSL (VDSL) typically works by dividing the frequencies used in a single phone line into two primary "bands". The ISP data is carried over the high-frequency band (25 kHz and above) whereas the voice is carried over the lower-frequency band (4 kHz and below).The user typically installs a DSL filter on each phone. This filters out the high frequencies from the phone line, so that the phone only sends or receives the lower frequencies (the human voice). The DSL modem and the normal telephone equipment can be used simultaneously on the line without interference from each other.

DSL technologies
The line length limitations from telephone exchange to subscriber are more restrictive for higher data transmission rates. Technologies such as VDSL provide very high speed, short-range links as a method of delivering "triple play" services (typically implemented in fiber to the curb network architectures). Technologies likes GDSL can further increase the data rate of DSL. Fiber Optic technologies exist today that allow the conversion of copper based IDSN, ADSL and DSL over fiber optics.

Example DSL technologies (sometimes called xDSL) include:

ISDN Digital Subscriber Line (IDSL), uses ISDN based technology to provide data flow that is slightly higher than dual channel ISDN.
High Data Rate Digital Subscriber Line (HDSL / HDSL2), was the first DSL technology that uses a higher frequency spectrum of copper, twisted pair cables.
Symmetric Digital Subscriber Line (SDSL / SHDSL), the volume of data flow is equal in both directions.
Symmetric High-speed Digital Subscriber Line (G.SHDSL), a standardised replacement for early proprietary SDSL.
Asymmetric Digital Subscriber Line (ADSL), the volume of data flow is greater in one direction than the other.
Asymmetric Digital Subscriber Line 2 (ADSL2), an improved version of ADSL
Asymmetric Digital Subscriber Line 2 Plus (ADSL2+), A version of ADSL2 that doubles the data rates by using twice the spectrum.
Asymmetric Digital Subscriber Line Plus Plus (ADSL++), technology developed by Centillium Communications for Japan market that extends downstream rates to 50 Mbit/s by using spectrum up to 3.75 MHz.
Rate-Adaptive Digital Subscriber Line (RADSL)
Very High Speed Digital Subscriber Line (VDSL)
Very High Speed Digital Subscriber Line 2 (VDSL2), an improved version of VDSL
Etherloop Ethernet Local Loop
Uni Digital Subscriber Line (UDSL), technology developed by Texas Instruments, backwards compatible with all DMT standards
Gigabit Digital Subscriber Line (GDSL), based on binder MIMO technologies[7].
(UHDSL) Universal Digital Subscriber Line using fiber optics. Developed in 2005 by RLH Industries, Inc. Converts HDSL-1, 2 or 4 copper service into fiber optic HDSL service.

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Q: What's the Difference Between Bluetooth and Wi-Fi?

A: Bluetooth and Wi-Fi are both wireless networking standards that provide connectivity via radio waves. The main difference: Bluetooth's primary use is to replace cables, while Wi-Fi is largely used to provide wireless, high-speed access to the Internet or a local area network.
Bluetooth

First developed in 1994, Bluetooth is a low-power, short-range (30 feet) networking specification with moderately fast transmission speeds of 800 kilobits per second. Bluetooth provides a wireless, point-to-point, "personal area network" for PDAs, notebooks, printers, mobile phones, audio components, and other devices. The wireless technology can be used anywhere you have two or more devices that are Bluetooth enabled. For example, you could send files from a notebook to a printer without having to physically connect the two devices with a cable.

A few notebooks, such as the IBM ThinkPad T30, now include built-in Bluetooth connectivity. And $129 will buy you a Bluetooth card for expansion-slot Palm PDAs, allowing you to connect to printers, notebooks, mobile phones, and other devices without cables.

Despite the promises of Bluetooth, however, hardware makers have been slow to incorporate it into their products. Some experts believe it could be eight years before Bluetooth is commonly used. They attribute the technology's lagging adoption rate to poor usability and confusion about what Bluetooth is and does. For more on that topic, read "Why We're Still Waiting for Bluetooth."
Wi-Fi

Short for Wireless Fidelity, Wi-Fi is a user-friendly name for devices that have been certified by the Wireless Ethernet Compatibility Alliance to conform to the industry-standard wireless networking specification IEEE 802.11b. Wi-Fi began appearing in products in late 1998. The standard currently provides access to Ethernet networks such as a corporate LAN or the Internet at super-fast speeds of up to 11 megabits per second.

Wi-Fi connections can be made up to about 300 feet away from a "hot spot" (slang for a Wi-Fi networking node). When your notebook or PDA has a Wi-Fi networking card or built-in chip, you can surf the Internet at broadband speeds wirelessly. Wi-Fi networking nodes are proliferating globally; many Starbucks locations, for instance, offer access to Wi-Fi hot spots for a fee. (See the Notebooks section in this newsletter for information on finding Wi-Fi hot spots.)

Many notebooks today have IEEE 802.11b built-in; those that don't can be adapted via Wi-Fi connectivity PC Cards. Wi-Fi is also the basis for some home networking products, allowing you to share high-speed Internet connections without cabling. Late last year, products featuring a newer wireless networking specification, IEEE 802.11a (called Wi-Fi5 by WECA), debuted. This standard provides transmission speeds of up to 54 mbps. Wireless networking is expected to grow in popularity as a practical, flexible way to replace some LANs. With wireless networking, for instance, workers can carry their notebooks from cubicle to conference room and stay connected to the corporate network.

For information about setting up a wireless home network, see "How to Set Up Your Home Network."

For more about the first IEEE 802.11a-based products, see "Wireless LANs Gain Speed at Comdex." In addition, Socket Communications, a network connections provider, has posted a helpful white paper that compares Bluetooth with Wi-Fi.

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Wi-Fi is a trademark of the Wi-Fi Alliance for certified products based on the IEEE 802.11 standards (also called Wireless LAN (WLAN) and Wi-Fi). This certification warrants interoperability between different wireless devices.

The term Wi-Fi often is used by the public as a synonym for wireless Internet (WLAN); but not every wireless Internet product has a Wi-Fi certification, which may be because of certification costs that must be paid for each certified device type.

Wi-Fi is supported by most personal computer operating systems, many game consoles, laptops, smartphones, printers, and other peripherals.

A Wi-Fi enabled device such as a PC, game console, mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points — called a hotspot — can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks, for example, in London. Both architectures can operate in community networks.

In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Organizations and businesses such as airports, hotels and restaurants often provide free hotspots to attract or assist clients. Enthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access. Metropolitan-wide Wi-Fi (Muni-Fi) alread has more than 300 projects in process. There were 879 Wi-Fi based Wireless Internet service providers in the Czech Republic as of May 2008.

Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.

When wireless networking technology first entered the market many problems ensued for consumers who could not rely on products from different vendors working together. The Wi-Fi Alliance began as a community to solve this issue — aiming to address the needs of the end-user and to allow the technology to mature. The Alliance created the branding Wi-Fi CERTIFIED to reassure consumers that products will interoperate with other products displaying the same branding.

Many consumer devices use Wi-Fi. Amongst others, personal computers can network to each other and connect to the Internet, mobile computers can connect to the Internet from any Wi-Fi hotspot, and digital cameras can transfer images wirelessly.

Routers which incorporate a DSL-modem or a cable-modem and a Wi-Fi access point, often set up in homes and other premises, provide Internet-access and internetworking to all devices connected (wirelessly or by cable) to them. One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router. Wi-Fi also enables places which would traditionally not have network to be connected, for example bathrooms, kitchens and garden sheds. The "father of Wi-Fi", Vic Hayes, stated that being able to access the internet whilst answering a call of nature was "one of life's most liberating experiences".

As of 2007 Wi-Fi technology had spread widely within business and industrial sites. In business environments, just like other environments, increasing the number of Wi-Fi access-points provides redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fi implementations have moved toward "thin" access-points, with more of the network intelligence housed in a centralized network appliance, relegating individual access-points to the role of mere "dumb" radios. Outdoor applications may utilize true mesh topologies. As of 2007 Wi-Fi installations can provide a secure computer networking gateway, firewall, DHCP server, intrusion detection system, and other functions.

Operational advantages

Wi-Fi allows local area networks (LANs) to be deployed without wires for client devices, typically reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs.

Wireless network adapters are now built into most laptops. The price of chipsets for Wi-Fi continues to drop, making it an economical networking option included in even more devices. Wi-Fi has become widespread in corporate infrastructures.

Different competitive brands of access points and client network interfaces are inter-operable at a basic level of service. Products designated as "Wi-Fi Certified" by the Wi-Fi Alliance are backwards compatible. Wi-Fi is a global set of standards. Unlike mobile telephones, any standard Wi-Fi device will work anywhere in the world.

Wi-Fi is widely available in more than 220,000 public hotspots and tens of millions of homes and corporate and university campuses worldwide. Wi-Fi Protected Access encryption (WPA and WPA2) is not easily cracked if strong passwords are used. New protocols for Quality of Service (WMM) make Wi-Fi more suitable for latency-sensitive applications (such as voice and video), and power saving mechanisms (WMM Power Save) improve battery operation.

Limitations

Spectrum assignments and operational limitations are not consistent worldwide. Most of Europe allows for an additional 2 channels beyond those permitted in the U.S. for the 2.4 GHz band. (1–13 vs. 1–11); Japan has one more on top of that (1–14). Europe, as of 2007, was essentially homogeneous in this respect. A very confusing aspect is the fact that a Wi-Fi signal actually occupies five channels in the 2.4 GHz band resulting in only three non-overlapped channels in the U.S.: 1, 6, 11, and three or four in Europe: 1, 5, 9, 13 can be used if all the equipment on a specific area can be guaranteed not to use 802.11b at all, even as fallback or beacon. Equivalent isotropically radiated power (EIRP) in the EU is limited to 20 dBm (100 mW).

Reach

Wi-Fi networks have limited range. A typical Wi-Fi home router using 802.11b or 802.11g with a stock antenna might have a range of 32 m (120 ft) indoors and 95 m (300 ft) outdoors. Range also varies with frequency band. Wi-Fi in the 2.4 GHz frequency block has slightly better range than Wi-Fi in the 5 GHz frequency block. Outdoor range with improved (directional) antennas can be several kilometres or more with line-of-sight. In general, the maximum amount of power that a Wi-Fi device can transmit is limited by local regulations, such as FCC Part 15 in USA.

Wi-Fi performance decreases roughly quadratically as distance increases at constant radiation levels.

Due to reach requirements for wireless LAN applications, power consumption is fairly high compared to some other short-range standards. Technologies such as Zigbee and Bluetooth, which are designed to support wireless PAN applications, provide a much shorter propagation range of

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Bluetooth is an open wireless protocol for exchanging data over short distances from fixed and mobile devices, creating personal area networks (PANs). It was originally conceived as a wireless alternative to RS232 data cables. It can connect several devices, overcoming problems of synchronization.

The word Bluetooth is an anglicized version of Old Norse Blátönn or Danish Blåtand, the name of the tenth-century king Harald I of Denmark and Norway, who united dissonant Scandinavian tribes into a single kingdom. The implication is that Bluetooth does the same with communications protocols, uniting them into one universal standard.

Bluetooth uses a radio technology called frequency-hopping spread spectrum, which chops up the data being sent and transmits chunks of it on up to 79 frequencies. In its basic mode, the modulation is Gaussian frequency-shift keying (GFSK). It can achieve a gross data rate of 1 Mb/s. Bluetooth provides a way to connect and exchange information between devices such as mobile phones, telephones, laptops, personal computers, printers, Global Positioning System (GPS) receivers, digital cameras, and video game consoles through a secure, globally unlicensed Industrial, Scientific and Medical (ISM) 2.4 GHz short-range radio frequency bandwidth. The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group (SIG). The Bluetooth SIG consists of companies in the areas of telecommunication, computing, networking, and consumer electronics.[

Bluetooth is a standard and communications protocol primarily designed for low power consumption, with a short range (power-class-dependent: 1 meter, 10 meters, 100 meters) based on low-cost transceiver microchips in each device. Bluetooth makes it possible for these devices to communicate with each other when they are in range. Because the devices use a radio (broadcast) communications system, they do not have to be in line of sight of each other.

Class 1 100 mW (20 dBm) ~100 meters
Class 2 2.5 mW (4 dBm) ~10 meters
Class 3 1 mW (0 dBm) ~1 meter

In most cases the effective range of class 2 devices is extended if they connect to a class 1 transceiver, compared to a pure class 2 network. This is accomplished by the higher sensitivity and transmission power of Class 1 devices.

More prevalent applications of Bluetooth include:

* Wireless control of and communication between a mobile phone and a hands-free headset. This was one of the earliest applications to become popular.
* Wireless networking between PCs in a confined space and where little bandwidth is required.
* Wireless communication with PC input and output devices, the most common being the mouse, keyboard and printer.
* Transfer of files, contact details, calendar appointments, and reminders between devices with OBEX.
* Replacement of traditional wired serial communications in test equipment, GPS receivers, medical equipment, bar code scanners, and traffic control devices.
* For controls where infrared was traditionally used.
* Sending small advertisements from Bluetooth-enabled advertising hoardings to other, discoverable, Bluetooth devices[citation needed].
* Two seventh-generation game consoles, Nintendo's Wii and Sony's PlayStation 3, use Bluetooth for their respective wireless controllers.
* Dial-up internet access on personal computers or PDAs using a data-capable mobile phone as a modem.

A personal computer must have a Bluetooth adapter in order to communicate with other Bluetooth devices (such as mobile phones, mice and keyboards). While some desktop computers and most recent laptops come with a built-in Bluetooth adapter, others will require an external one in the form of a dongle.

Computer requirements

Unlike its predecessor, IrDA, which requires a separate adapter for each device, Bluetooth allows multiple devices to communicate with a computer over a single adapter.

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As the worlds energy crisis becomes more and more obvious, the importance of reducing society's dependence on non-renewable energy sources like fossil fuels is more and more urgent. Non-renewable energy sources are on the way out. Renewable energy sources, such as a home wind turbine, can put out energy cleanly and without using up rapidly depleting sources. There are three types of renewable sources to look out for: solar, hydro, and the most promising, wind.

The sun is the most abundant energy source on Earth. It's free and unlimited. Solar power solutions are currently being developed to be more cost efficient and widely available. Many predict that this will be one of the biggest energy suppliers in the future. Solar systems are environmentally friendly as well as very low maintenance. The sun has always been the main supply of energy to the earth and hopefully in the future we can harness this great power.

Hydro energy is currently the most popular renewable energy source. In the future however, this is likely to change. Although hydro energy is clean and efficient, it is extremely detrimental to local environment and ecosystems. Although hydro energy is being developed to operate cars and appliances.

By far the best and most promising solution is wind energy. For around $200 dollars, anyone can set up a small home wind turbine and begin harnessing the wind to power their home. wind is completely clean and efficient. Before wind was too expensive to employ at the consumer level but with recent technological advancements, virtually anyone can begin using it. There is a low start up cost and very little maintenance. The future is here when it comes to wind power.

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DVD, also known as "Digital Versatile Disc" or "Digital Video Disc," is a optical disc storage media format. Its main uses are video and data storage. Most DVDs are of the same dimensions as compact discs (CDs) but store more than six times as much data.

Variations of the term DVD often describe the way data is stored on the discs: DVD-ROM (Read Only Memory), has data that can only be read and not written, DVD-R and DVD+R can record data only once and then function as a DVD-ROM. DVD-RW, DVD+RW and DVD-RAM can both record and erase data multiple times. The wavelength used by standard DVD lasers is 650 nm,[1] and thus the light has a red color.

DVD-Video and DVD-Audio discs respectively refer to properly formatted and structured video and audio content. Other types of DVDs, including those with video content, may be referred to as DVD-Data discs. As next generation high-definition optical formats also use a disc identical in some aspects yet more advanced than a DVD, such as Blu-ray Disc, the original DVD is occasionally given the retronym SD DVD (for standard definition).

DVD uses 650 nm wavelength laser diode light as opposed to 780 nm for CD. This permits a smaller pit to be etched on the media surface (0.74 µm for DVD versus 1.6 µm for CD) compared to CDs, allowing for a DVD's increased storage capacity. In comparison HD DVD and Blu-Ray, the successors to the DVD format, use a wavelength of 405 nm.

Writing speeds for DVD were 1×, that is 1350 kB/s (1318 KiB/s), in the first drives and media models. More recent models at 18× or 20× have 18 or 20 times that speed. Note that for CD drives, 1× means 150 KiB/s (153.6 kB/s), approximately 9 times slower

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What is GPS? The acronym stands for Global Positioning System. It is the new "Polaris" that aids in navigating, positioning and tracking with the use of a satellite-controlled system that broadcasts signals to the equipment on the ground. With receivers hand carried by users, GPS determines the exact location of a vehicle, person or assets and other things useful and valuable to which it is attached and records the position at regular intervals. It is a powerful tracking system that has provided the world with diverse applications for the military and civilian users.

What is GPS? The GPS is a space-based radionavigation system controlled and funded by the U.S. Department of Defense and operated by the U.S. Military. This is the GPS Operational Constellation. The tracking system has space segments consisting of GPS satellites sending signals coming from space. There can be at least 24 operational satellites orbiting in 12 hours that recapitulate the same ground track as the earth turns underneath them. The GPS satellites then transmit the data in a very precise time reference plied by what is called "atomic clocks" onboard the satellite. These atomic clocks then passively transmit the navigation messages in specially coded signals, enabling the equipment on the ground called "receivers" to compute position, time, direction and velocity in three-dimensional locations known as latitude, longitude and altitude.

What is GPS? Your Most Reliable and Most Precise Assistant

The GPS was primarily for the use of the military. However, after the Korean Flight 007 in 1983 tragedy, which would have been prevented had its crew only had access to better navigational tools, President Ronald Reagan issued a directive which would guarantee that GPS signals be made available to the world for free or without restrictions. Though it was intended for civilians as well as military applications at first, from its design, civilian users would not be getting the same accuracy that the military could.

Going public, what is GPS serving the commercial market? GPS became the new powerful tool that improved efficient routing of vessels at sea. It has saved a ship's navigator hours of celestial inference and calculation. GPS enhanced safety at sea made it possible to report precise position to rescuers in case of disasters.

What is GPS navigating the land? GPS also improved efficiency on land: delivery trucks can now receive GPS signals and easily transmit their position back to a central dispatcher; police and fire departments use GPS to efficiently dispatch their vehicles and reduced response time; GPS keeps motorists from getting lost by showing their position and intended route on dashboard displays; railroads now use GPS technology in replacing older maintenance-intensive mechanical signals.

What is GPS navigating the air? Long before the GPS, aircrafts typically fly from one waypoint to another and pilots on long-distance flights relied on navigational beacons situated across the country. The dawning of GPS supplemented existing navigational techniques for aircrafts inexpensively. With GPS navigating the air, airplanes can now fly a direct route to a destination that save significant amount in consumption of fuel and time, the methods of guiding planes to a safe landing in a poor weather or visibility has been improved and simplified and aided pilots with a precise position data to keep the plane on course.

What is GPS surveying, mapping the earth, managing the land and agriculture? GPS is used by surveyors and map makers for precision positioning; map locations of such facilities as telephone poles, sewer lines, and fire hydrants; map construction sites and property lines in minutes. In mapping the earth, GPS points have assigned codes in order to identify roads, streams, or other objects during data collection for analyses and comparison through a computer program called "Geographic Information Systems (GIS)."

GPS can be used in forestry, for mineral exploration, and wildlife habitat management to define positions of important assets precisely and identify their changes. In agriculture, a farm equipment with GPS receivers can provide precise position information and it also gives farmers great accuracy in the application of fertilizers and harvesting crops.

Agricultural GPS systems can be used to create crop yield maps during harvesting, making it easy for farmers to plan exactly how the fields should be used and fertilized for future crops.

So, what is GPS? It is a powerful navigational tool acting as your most reliable and most precise assistant that is transforming the way nations operate in space.

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When television was first created, it was in black and white and nobody believed it would ever enter the home of almost every citizen in the United States. While technology developed over the next many years to add features such as color pictures, stereo sound, and remote controls, the concept of the television remained largely unchanged for many years. The VCR was one of the first revolutionary changes, and satellite television was developed as a means of offering consumers the same channels nationwide. Right from its inception, satellite TV has been a revolutionary concept, and the technology has stayed on the leading edge of television ever since.

From the days of big, UFO shaped dishes to the modern models that attach to the side of a home; satellite has changed not just with the times, but in many cases ahead of them. Satellite has offered television services in areas where no other service was available since the 1980's and continues to do so to this day. Where cable runs via a complex series of underground wires, satellite operates over the airwaves, requiring only a dish, a receiver, a television, and a clear view of the southern sky.

In addition to smaller dishes, satellite has also stayed with the times in being among the first services to offer services such as Pay per View and OnDemand, both of which are now staples for most television viewers. Satellite was one of the first services to offer Digital Video Recorder services, and continues to expand upon this technology all the time. Satellite now offers the service in HD and is the only service provider that currently allows DVR boxes to be scheduled from computers or mobile phones.

Satellite also offers service to planes, boats, and recreational vehicles, a revolutionary achievement offered by no other television provider. The most recent portable television innovation is a small screen and receiver called the Sat-Go, which is roughly the size of a laptop computer and is capable of receiving all subscribed satellite channels. The technology has received much praise and is quickly becoming a favorite among travelers, campers, and sports fans alike.

In short, satellite television is truly a revolution and has been since the beginning. The pioneer in bringing multiple channels to customers across the country, satellite has always had the most to offer. These days, satellite companies are still hard at work developing new technologies. Satellite currently offers the most exclusive and high definition programming of any television service provider as well as the world's most popular paid sports packages, such as the perennial favorite NFL Sunday Ticket. DVR and HD-DVR services couple with the clearest signal and the most interactive features to create a truly superior viewing experience while extensive Pay per View and OnDemand libraries offer more choices than the competition. It is uncertain what technologies lie ahead in the future of television, but if the past is any indicator whatsoever, there is little doubt that satellite will be the first to perfect it and bring it to the masses.

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'Voice Over Internet Protocol' or VOIP routes voice conversations over the internet or any other IP-based network. VOIP's greatest contribution is the greatly reduced costs, especially for those companies which are call based. This technology provides opportunities to streamline the office communication, with efficient voicemail, call routing, voicemail to email, and auto-answering systems. Most offices switching over to VOIP, site reasons such as cost effectiveness in comparison to PBX systems as one of the major reasons for the change. There are three types of VoIP these being, pc-to-pc VoIP, a soft phone and a monthly VoIP service

This latest technology has several interesting advantages that make it a novelty. ‘Virtual numbers' are those numbers that you can access on your phone but have a different area code. VOIP also facilitates ‘Call filtering', by which you may decline calls that are unidentified or unknown. ‘Call hunting' is a facility, which makes it possible for incoming calls to dial different numbers if you are not available at home.

An ‘upgraded voice mail', you can use through the internet, or even get forwarded to your cell. Another VOIP facility would be ‘Conference calling' to about ten other lines. A ‘Do Not Disturb' facility is also available which allows one from barring incoming calls when you don't want to.

Like any new technology that needs the passage of time to prove itself, the VOIP is surrounded by a shroud of questions that often arise in the mindset of the average new user, so used to his regular PBX system. Industry experts believe that there are plenty of reasons to be wary of this new technology. According to them it eats up bandwidth at a dangerous pace. It can also make the systems susceptible to e-mail or a virus attack leading to complications for Oracle users too. There is another industry opinion that argues that VoIP phone sets have far fewer desired options and features than PBX phones. Apart from this slowing down the entire net work is an associated concern for all industrial concerns

Surveys have shown that 36% of 106 respondents want to use VoIP only in some parts of their organizations. Again another 27% said that they will eventually move entirely to VoIP. Another 22% said that they would deploy VoIP only in remote or field offices in the outskirts. Some others are of the belief that VoIP systems can make enterprises more vulnerable, experts warn that it is necessary to have very good messaging security to prevent exploits that could occur as a result of VoIP. At times vendors promise big cost savings but one should be wary of the actual results.

VOIP, as an industry trend is stable and here to stay. Some of the VoIP service providers might not be very stable since the industry is still in its nascent stages, yet there are plenty of companies which have entered the market in the last two or three years. In the ensuing completion there would probably just some of the bigger companies, in a case of the ‘survival of the fittest' which will actually absorb the smaller companies and help in making the market a more competitive one.

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Computer skills are very essential these days, because computers are widely used in almost all the business fields. Improving your computer skills can mean improving your career prospects for the future. For this reason, irrespectively of your field you have to learn computers.

Learning to use a personal computer is not that difficult. If you have never used a computer before, you may find it intimidating. However, with a little practice, it is very easy to use the computer. The best way to learn to use a computer is by fiddling with it and learning by doing. You may also consider joining a computer training course to accelerate your learning.

Computer software are usually developed with the common user in mind. Operating systems like the popular Windows have a graphical user interface. This makes the operation of the computer very intuitive. All that you have to do is point and click on the icons using the mouse to navigate around the files and folders and to open programs. There is no need to remember any commands.

Once you master to use the basics of the computer, it is time to learn more advanced programs like word-processors, accounting software, etc. You may also consider investing your time in learning programming languages. Programming languages are a little difficult to learn. However, with practice and lessons, it is possible to master these within a short time.

There are many introductory books on computers. Buying and going through some of these books may be very beneficial. There are also many websites on the Internet that provide information on various computer topics. Search for such sites and practice the information provided there to improve your computer skills. You may also consider joining a computer user group for mutually learning from others.

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Human beings are endowed with the most developed brain of all the species to ever inhabit this planet called the earth. This unique feature makes the humans to continually seek change and development. The ever lasting thirst of knowledge and to improve efficiency has led them to the discovery of artificial intelligence; the computer technology.

The computer or information technology has had a profound impact on almost all the aspects of the human life since its inception. Not only the social aspects are affected but also the financial ones too are profoundly influenced.

The computer technology which can be considered as a recent phenomenon when viewed on the scale of history of the world, has made progress in leaps and bounds in a matter of a mere decade or so. No one could have imagined the true affect of this emerging technology only a short while ago.

Internet is the biggest pawn of the computer technology. With just a click of a button, a vast universe of information is opened in front of the user and that too in the privacy of ones own home or office. There is a wide array of search engines available which have the ability to fetch massive loads of required information within a fraction of a second. The latest web applications which are undergoing rapid changes are targeting more interactive options. Today the focus is to provide safe, convenient and user friendly applications.

Not only the internet acts as a highway for information, it is a magical means of communication between friends and family and can bridge a gap of thousands of kilometers. The distances are shrinking and the whole world has become one big global village.

E-commerce is yet another useful utility which is ever evolving and is making its effect felt in the financial sector. The user has the option and power to transact with the vendors in a secure environment and the deals can be closed within seconds.

The education sector is one big beneficiary of this marvelous technology. Accumulation and sharing of knowledge related to social as well as the technical subjects has transformed the way of imparting education, thanks to the computer related technologies. Not only the stand alone computer tools are a useful accompaniment to the education, but also the networked systems are a convenient and efficient means of knowledge accumulation and sharing.

The industries too are utilizing the information technology not only for maintaining data bases but also in their manufacturing processes. The use of this technology not only makes the management much easier for the stake holders but also translates into much better revenue generation.

The developments in the software and the hard ware both have been phenomenal in the recent years and the trend is expected to continue into the future with more momentum and to have profound effects on the human social as well as financial aspects.

Thus one can safely vouch that the future of the information technology is by all means very promising which will have even more enhanced positive effects on the lives of the modern day human beings.

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