Computer printer

The basic purpose of a computer printer is to produce a hard copy of documents stored in electronic form. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most newer printers, a USB cable to a computer which serves as a document source. Printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast; and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine. Printers are routinely classified by the underlying print technology they employ; numerous such technologies have been developed over the years. The choice of print engine has a substantial effect on what jobs a printer is suitable for, as different technologies are capable of different levels of image/text quality, print speed, low cost, noise; in addition, some technologies are inappropriate for certain types of physical media The speed of early printers was measured in units of characters per second. More modern printers are measured in pages per minute. These measures are used primarily as a marketing tool, and are not well standardised. Usually pages per minute refers to sparse monochrome office documents, rather than dense pictures which usually print much more slowly. PPM are most of the time referring to A4 paper in Europe and letter paper in the US, resulting in a 5-10% difference.

Do Snakes have Ears?

Snakes don't have ears that we can see. They don't have ear holes either. So you'd never know from looking at a snake that it has ears. But snakes do have a kind of ear that's inside their head. It's located near the lower jaw. A snake can hear noises but not very well. It doesn't hear noises coming through the air as humans do. What a snake can hear is vibrations that come through the ground. These sound waves pass from the ground to the bones of the jaw and then to the bones of the ear. That's the way the snake picks up sounds. Snakes do not appear to have ears. There are many animals that don't appear to have ears but that really do have them.

Why Do Hippopotamuses Always Stay in the Water?

The hippopotamus has skin that's thinner than other animals' skin. This means moisture is lost very easily. If a hippopotamus didn't keep itself wet, its body would dry out, and then it would die. The hippopotamus stays under the water's surface all day to stay wet. Its eyes, nose and ears are near the top of its head so it can stay almost completely underwater. Since the skin of the hippopotamus is extremely thin, moisture is easily lost, so it stays under water all day. Otherwise it would suffer from dehydration. The nostrils and ears of the hippopotamus can be closed so that water does not enter when the animal submerges. The hippopotamus moves with great agility in the water and can submerge to depths of more than 35 feet (11 m). It can stay down for periods of five minutes or more.

Compact Disc

The compact disc is a spin-off of the Laserdisc technology. Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc"in Eindhoven, The Netherlands on March 8, 1979. Three years earlier, Sony first publicly demonstrated an optical digital audio disc in September 1976. In September 1978, they demonstrated an optical digital audio disc with a 150 minute playing time, and with specifications of 44,056 Hz sampling rate, 16-bit linear resolution, cross-interleaved error correction code, that were similar to those of the Compact Disc introduced in 1982. A Compact Disc (also known as a CD) is an optical disc used to store digital data, originally developed for storing digital audio. The CD, available on the market since October 1982, remains the standard physical medium for sale of commercial audio recordings to the present day. A CD is made from 1.2 mm thick, almost-pure polycarbonate plastic and weighs approximately 16 grams. From the center outward components are at the center (spindle) hole, the first-transition area (clamping ring), the clamping area (stacking ring), the second-transition area (mirror band), the information (data) area, and the rim.

Windows Media Player

Microsoft Windows has had a media player since 1991, when Windows 3.0 with MultiMedia Extensions was released. This version of Windows, which was included with "Multimedia PC"-compatible machines but not available for retail sale, included the Media Player application, was capable of playing .mmm animation files, and could be extended to support other formats. Windows Media Player (abbreviated WMP) is a digital media player and media library application developed by Microsoft that is used for playing audio, video and viewing images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices. Editions of Windows Media Player were also released for Mac OS, Mac OS X and Solaris but development of these has since been discontinued. Allows the user to connect, share and sync data with portable handheld devices and game consoles. Media can be optionally transcoded to a format better suited for the target device, automatically, when synchronizing.

The Telephoto Lens-Photography

A telephoto lens takes in a narrower field of view than the standard lens, and renders what it photographs on a larger scale. It magnifies in the same way as binoculars or telescopes do, and it does so by a degree which is dependent on the relationship of its focal length to that of the standard lens. Thus a telephoto lens of 135mm providees an image rather more than 2.5 times larger than a standard lens of 50mm focal length; a 200mm, telephoto will magnify the subject four times. The telephoto lens is of particular value to sports and natural history photographers. With it they can photograph subjects they cannot approach closely. Photographers who use a telephoto lens a good deal use what is known as a bean bag to help steady the bulky lens and camera combination. Telephoto lenses take some getting used to, but when properly handled they can present the photographer with a very valuable aid to composition. By excluding much foreground detail the telephoto lens presents a distant part of the scene before the camera as if it were close to.

UPS

We all know how much necessary UPS are when it comes to personal computers and other devices. UPS stands for uninterruptible power supply. It is generally a battery back-up. UPS is typically used to protect computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or data loss. It provides emergency power and, depending on the topology, line regulation as well to connected equipment by supplying power from a separate source when utility power is not available. The general categories of modern UPS systems are on-line, line-interactive, and standby. An on-line UPS uses a "double conversion" method of accepting AC input, rectifying to DC for passing through the battery (or battery strings), then inverting back to AC for powering the protected equipment. The Offline / Standby UPS (SPS) offers only the most basic features, providing surge protection and battery backup. Usually the Standby UPS offers no battery capacity monitoring or self-test capability, making it the least reliable type of UPS since it could fail at any moment without warning.

Interiors-Photography

Most people have a hobby of one sort or another, and the camera is often an indispensable accessory, helping get the most out of other specialist interests. This is true particularly if the interest happens to be in architecture, when it might be possible to visit certain fine buildings only very rarely. The camera can readily record stained glass windows, architectural detail, and grand views inside impressive cathedrals. If we are going to shoot a great many interiors we should equip our self with a single lens reflex camera, a wide-angle lens, a modest telephoto, a tripod, a cable release and a flash unit with a long extension lead, allowing it to be fired away from the camera. If we are photographing in a large building such as a cathedral we can set our camera on its tripod at the back of the building and set the shutter to B for a time exposure. Stained glass windows display their beauty when light shines through them from outside so do not spoil the effect by using flash. An easy way to photograph a fine ceiling is to lay the camera on its back on the floor, making a time exposure if necessary.

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Headphones

Headphones are a pair of small loudspeakers, or less commonly a single speaker, with a way of holding them close to a user's ears and a means of connecting them to a signal source such as an audio amplifier, radio or CD player. They are also known as earphones, earbuds, stereophones, headsets or, informally cans. In the context of telecommunication, the term headset is used to describe a combination of headphone and microphone used for two-way communication, for example with a telephone. The telephone earpiece such as the one pictured at the right was common around the turn of the 20^th century. From the earpiece developed the headphones. Sensitive headphones were the only way to listen to audio signals before amplifiers were developed. Headphones can be used both with fixed equipment such as CD or DVD players, home theater, personal computers and with portable devices (e.g. digital audio player/mp3 player, mobile phone, etc.).There are many different types of headphone designs, with the listening situation and the needs of the listener determining what type of headphone will be used. Generally, headphone formfactors can be divided into four separate categories: circumaural, supra-aural, earbud, and in-ear.

Why doesn't dry Ice Turn to Water the Way Regular Ice Does?

Regular ice is made from water. When it melts it turns back into water. Dry ice is not made from water. Instead it is made from the gas called carbon dioxide. This gas is in the air around us. It is what dry ice turns into when it melts. The transformations of water from one of its three states-solid, liquid or gas-is brought about by changes in temperature. For a complete three-state transformation to occur in carbon dioxide, changes in both temperature and pressure are requir3ed. At normal atmospheric pressure and below -109 degree Fahrenheit. (-78.5 degree Celsius.) Carbon dioxide is a solid, in the form of dry ice, but above that it is a gas. At normal room temperature dry ice turns into a colorless gas. The white vapor that it seems to give off is actually cooled air around it.

How Do Snakes Move Along?

Snakes have scales under their bellies. They use these scales to help them move forward. Snakes have long, thin bodies. In the place of legs they have scales that envelop their bodies and help them o go forwards. Some like the Indian python, erect the scales to move, but others move by stretching, then contracting their bodies. A number of them move by undulating their bodies, always with the entire body touching the ground. Snakes lay eggs in the ground, where the heat of the earth hatches them. As they grow their skin becomes too tight, so they shed it and leave it behind. A new skin is there to take the old one's place. Snakes are good swimmers. They swim by moving their body from side to side in the water like they crawl.

How Does Our TV Work?

TV programs come through the air on electrical waves. The antenna on our roof gathers the waves. Your TV uses light to turn them into pictures. Television is a complicated technology that has become part of our daily lives. The camera-broadcast source breaks down light into FM radio waves, which are then transmited to the home from the TV station's tower. The television tube makes them back into pictures by shooting electron beams at its surface from behind. The rays strike phosphor bits all over series of still pictures very fast, a bit like movie film. In the studio a big camera first turns the picture into electricity. Sounds go with it over wires from the studio through a large control room.

Why Can We Talk by Telephone?

All voices and sounds make vibrations. The telephone changes these into electric patterns to go on the wires. Other phones make them into sounds again. Sound is a phenomenon of vibration and the telephone uses this principle to convert the vibrations of your voice into electrical signals that can travel over wire. A telephone actually has a small microphone in the speaking end of the headset and tiny speaker in the earpiece. A phone cal creates two circuits: microphone to speaker at each end. Many new refinements are being added; we already talk by satellite, and soon our voices will travel on light waves.

Why Can't We See Clearly through Frosted Glass?

The glass is rough on one side so light can't go straight through. If light is mixed up, the things we see are too. Transparent glass allows rays of light pass through it without bending, and the images they carry are seen clearly. The unevenness of frosted glass directs the rays into random patterns, so images cannot be seen distinctly. Frosted glass was formerly made by placing tiny bits of hard sand on the surface itself, but today machines blow the sand over the surface to erode it. Light bulbs and other small items are frosted with hydrogen fluoride, a gas that corrodes glass. The surface of frosted glass is made rough by putting many small scratches in it. The reason light bulbs are white is because they're frosted, too. But they don't use sand to make them. They use chemicals.

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Why Are There Holes In an Abalone's Shell?

The holes in an abalone's shell let water flow in and out. That's important because an abalone has to take oxygen out of the water with its gills inside the shell. The abalone fastens itself to a rock and doesn't move around. So the hole let it get rid of its waste, which flow out with the water. And when the abalone lays eggs they come out through the holes in the shell. The abalone once was though to be half of a broken bivalve. Actually, it is a spiral shellfish. Holes in the abalone's shell allow water to pass in and out, permit the elimination of wastes, and are openings through which eggs are discharged into the water. An abalone crawls along rocks and eats seaweed that grows on them. Its mouth is in front, on the underside of its body.

Why Do Some Birds Migrate?

We say that birds migrate when they leave one are and fly to another. They may migrate because a place becomes too cold for them or there's no longer enough food. When the seasons change and there's more food the birds fly back to their first homes. Migration refers to the annual round trip that birds make in response to seasonal changes in their food supply. Almost half of the world's birds migrate. The greatest of these travelers is the arctic tern, which nests in the northern polar regions. During the eight months in which the term is not nesting its migratory fight to and from Antarctica may cover nearly 24, 000 miles (38, 623 km).

The Healthy Way.

Orange: A good source of vitamin C. Experts say a glass of orange juice can help prevent repetition of kidney stones.

Pineapple: Packed with most vitamins and minerals, pineapple juice is a very good source of an enzyme bromelain, which aids digestion.

Apple: Contains antioxidant, which help prevent the body from developing various types of cancer, as well as heart diseases.

Peaches and Plums: Contain good amount of vitamin C, beta carotene, antioxidant phytochemicals and anthocyanins all of which help to eradicate free radicals from the body.

Litchi: Helps prevent dehydration and keeps the body cool.
watermelon: Not only helps to quench thirst but is also a good source of beta carotene, vitamin C, pectin, lycopene, potassium and iron.

Guava: Helps control blood pressure, lowers cholesterol, battles diabetes, combats cancer.

Grape: Helps deal with fatigue and stress, cleanses the kidney and liver and lowers cholesterol.

Papayas and Mangoes: Excellent source of vitamin C, beta carotene, vitamin A and fibre.

Apricot: Very cooling during fever. Besides quenching thirst it eliminates waste products from the body and tones up eyes, stomach, liver, heart and nerves. Experts suggest that it also strengthens heart muscles.

How are Cups and Plates Made?

Cups, plates, bowls and many other table things are made of clay. Water is mixed in, and soft clay is given a shape. It is then hardened by baking it in an oven. For ceramics that are to be used in the household, a special clay is mixed with substances like mica, feldspar or silica, depending on the use and finish planned. The clay is shaped on a potter's wheel or in a press, then is dried and finally fired in a kiln. This produces and unglazed ware such as that used for plant pots. To finish dinnerware, glaze is applied and the piece refined. Porcelain is thinner and harder than earthenware. It is translucent and rings clearly when struck.

Why Does a Fan Make a Breeze?

The fan has blades that are slanted, not flat. when they turn very quickly, they blow the air at us. the electric fan produces a breeze because of the way its blades are curved. The angle of the blade's face will push air out; and of course the higher the speed, the more air is sucked in from behind and pushed out to the front. Airplane propellers work on this principle, but in reverse. We can demonstrate this with a hand-held fan: if its flat side is facing us, moving it side to side will produce no breeze. Angling one side 45 degree toward we will produce a nice breeze. When there id no breeze, the air that surrounds our bodies gets fast as hot as our bodies themselves. On a hot day, that doesn't feel good. A breeze blows this hot air away from us, and air that is cooler takes its place. That's why a breeze feels so good to us when it's hot.

Microsoft Promises less Complexity in Windows 7.

The launch of the final version of Windows 7 is around the corner, with Microsoft making available for public download the Release Candidate (RC) of the operating system (Os) earlier this month. The OS is now "entering the final phases of development and is ready for IT pros to evaluate Windows 7 and examine how it will operate in their environment," says Microsoft. So, we now know more or less what is in the offing with Windows 7. And the question which many Windows users will ask is: what is really different with it, compared to the existing versions of the OS they are now using probably either Windows XP or a Vista? "Less waiting, fewer clicks, and less complexity," is the promise that Microsoft holds out for the latest version. "Hundreds of little improvements and a few big ones that add up to a whole lot less," is what it had to say about the scale of the changes.

Vacuum Flask-Is This a Magic Bottle?

A vacuum jar keeps water hot i two ways. It has an inside like a mirror, which bounces heat back into the water. And the space around it has no air-so heat can't go anywhere! Inside a vacuum flask is a double-wall glass jar. Its surface is metal-coated to make a mirror, which reflects the heat (or the cold) back inside. Between the walls there is no air, so heat won't transfer to the outside. Portable flasks may use plastic or metal instead of glass, so dropping or any other shocks won't break the jar. Vacuum flasks are normally used for liquids, but there are flasks that are made with wide mouths to carry hot or cold food.

Did You Know That Oceans Flow?

Though most water in the oceans appears to be standing still it is always moving in what we call currents. All oceans have currents, which are much like the currents that we see in rivers. Some currents are caused by winds, such as prevailing winds and monsoons, blowing across the ocean's surface. As these strong winds push across the surface of the ocean, the raise the water into waves. Rather than traveling directly downwind, these waves will turn to one side. Depending on whether the currents are in the northern or southern hemisphere they will be deflected either to the right or to the left. This deflection, caused by rotation of the earth, is known as the Coriolis effect, named after the French mathematician. The spinning of the earth keeps the waters in motion and is another cause of ocean currents.

Why Does Breath Turn White?

The air we breathe out has a lot of water vapor in it. In cold places this hot, moist air cools in the cold and turns into small water droplets. The droplets look white, something like mist. When the air can absorb no more moisture we say that it has reached the saturation point. The higher the temperature, the more moisture the air can hold. But even on the hottest day, if too much water evaporates into the air it simply cannot be absorbed. When this happens the vapor that is not absorbed remains in the form of droplets, which appear as white mist. In a warm room our breath wouldn't look white. In the sunshine our breath would not be white unless it's very cold. On cold mornings in the shade it would be easy to see our breath.

Did You Know That Some Fish Build Nests like Bird Nests?

The stickleback uses the stalks and roots of water plants to make a round nest that looks just like some birds' nests. The male stickleback builds the nest and then invites a female into it. The female enters the nest, lays her eggs and swims away. The male then looks after the eggs until they hatch into young fish, called fry. He also looks after the fry until they're old enough to swim away on their own. Most sticklebacks, sometimes called tittlebacks, have nine spines along the back. In spring and early summer the male prepares for the mating se4ason by building a nest a short distance above the river bed or sea bottom. The female lays 20 to 30 eggs in the nest at one time. The male has a very strong territorial instinct and does not allow enemies or rival males to approach his nest.

Why Don't Chickens Fly?

Chickens used to fly when they lived in the wild. After men started taking care of them there was no need to fly, so the chickens stayed on the ground. That made their flying muscles so weak that finally they were unable to fly. With men feeding them and keeping them safe, they had little worry about enemies, so they didn't need to fly. They didn't forget how to fly, but their muscles got too weak for it. Another reason is that they got fat and heavy. After men started keeping chickens they wanted to make them nice and plump so they would be good to eat. So they gave them a lot to eat, and with no exercise the chickens' wings became so weak that they could not lift hose heavy bodies. Even today, however, if they were kept in free range conditions they still might be able to fly a vertical distance of a few meters, but they would be quite unable to remain in the air for long periods.

How Do Barnacles Eat When They're Fastened to Rocks?

Many kinds of sea animals fasten themselves to rocks along the shore. When the tide is out, they keep their mouth tightly closed. When the tide comes in it covers the rocks with water. That's when they open their mouth and start eating. The oceans tides ebb and flow twice a day. Places on rocky shores that are underwater at high tide are exposed when the tide goes out, and tidal pools. Several kinds of barnacles and a number of other animals can live on the exposed rocks, entirely out of water, for the short time until the next tide. When waves beat against it some barnacles opens its mouth and eats small water animals. When it is covered by the sea some barnacles uses its legs to catch small animals living in the water. When the tide is in some extends its hair like tentacles and catches tiny marine organisms.

Why Do Elephants Live in Herds?

Elephants form herds or groups made up of only females and their young. The oldest female becomes the leader, and all the others follow her for their protection. An elephant herd is composed of females related by blood, plus their young. All the adults are sisters, or mother and daughter. The herd forms extremely close bonds, and the members assist one another in many ways. The herd follows a leader, which is the oldest female. She uses her years of experience to assure the safety of the herd as a whole. For example, the leader knows the feeding grounds, watering holes and ways to combat enemies. It is noteworthy that although elephants have a lifespan of about 60 years, such an age is not usual in the wild. Half die by the age of 15, and only about one elephant in five reaches the age of 30. When the young have grown the females remain with the herd, but the makes leave to begin an independent life. Only in mating season are the males allowed close to the herd.

What Do Foxes Use Their Tails For?

A mother fox uses her tail as a signal for her pups to follow. The tip of a fox's tail is white. When the mother fox raises her tail it's very easy for the small foxes to see it. They can follow her easily without getting lost. Some animals use their tail as a signaling device so that members of a herd or a mother and its young will not get separated. The tail often has white fur on it so that it can be seen easily even in thick underbrush or in the dark. Animals that have to chase nimble prey use their tail to help keep their balance when they suddenly change direction. In the winter, when its fur grows thicker, and animal uses its tail like a muffler to keep itself warm.

Why Don't Bananas Have Seeds?

Bananas did have seeds at one time. But the seeds made them hard to eat. So the people who grew the kind of bananas that we like to eat found a way to make them without seeds. Even now there are still some types of bananas that have seeds. In fact many varieties of wild bananas growing in Southeast Asia and other warm areas have large seeds from which new plants are generated. But the seedless cultivated bananas are planted from cuttings. Seedless grapes are produced by dipping their flowers into a chemical. In a similar manner watermelons are rendered seedless by chemically treating their seeds.

Bluetooth!

This way of connectivity is most probably used for mobile devices over short distance in a fixed way. One can exchange data over a short distance. Bluetooth is also a wireless connectivity like Wi-Fi. It is also said that bluetooth are alternative for RS232 data cables. Has it replaces the data cables, this way of connection is also very important and considered to be vital. It uses a radio technology called frequency hopping spread spectrum. One can exchange information between devices like mobile phones, telephones, laptops, personal computers, printers, digital cameras and many more in a shortest and fixed distance.

Bluetooth can be of three classes namely class 1, class 2 and class 3. The range of class 1 would be 100 metres, class2 would be 10 meters and class 3 would be 1 meter. A computer should have a bluetooth adapter in order to communicate with other bluetooth devices. After setting up connection, bluetooth generally lists the information like device name, device class, lost of services and some technical information.

Modern Motherboard

Motherboard is the one that supplies power to all the parts of a computer. Without a motherboard their is no computers. One cannot make computer work without motherboard. It connects all the parts of a computer and make them communicate with one another. The motherboard that has launched for the first time has got only a processor and card slots. With the rise in the technology the newer motherboard has got many a parts in it, that makes a computer most effective. It is to be noted that the shape of the motherboard is said to be "form factor".

A modern motherboard has got PCI, AGP, North Bridge, Processor socket, memory, IDE, South bridge, BIOS and SATA.

PCI - Peripheral Component Interconnect, the main purpose of this is, it act as a connection for video, sound and video capture cards.

AGP- Accelerated Graphics Port, this slot act has a dedicated port for video cards.

IDE- Integrated Drive Electronics, it act has a interface for the hard drives.

Java Platform

This is one of the programming language that exits in all the computers, consumer gadgets and other devices. Without Java, technology would have not grown to the level what we see now. Java platform is a new way of computing, that is based on network power. It works almost everywhere.

It works from the smallest devices to super computers. An important thing about Java is that it work on any devices that supports Java platform. There can be web browsers without Java, but there cannot be a effective web browser without Java.

Many of the IT companies currently depends only on Java of their huge projects. Java allows you to play online games, One can calculate mortgage rates and many more. It is stated that more than 6.5 million software developers are attracted towards Java technology. The reason for these software developers to depend on Java is because, with the help of Java one can write software on one platform and can run it in any other platform. One of the latest thing about Java is JavaFx. JavaFx allows the developers to use any Java library within JavaFx applications.

When it comes to programming, name of a class and the program file name should be same when it comes to Java. Java does not support multiple inheritance, which is one of the disadvantage of Java.

Wi-Fi connectivity

From the name, it is clear that Wi-Fi is nothing but a wireless connection. It is generally used for Internet connection(WLAN). WLAN stands for wireless local area network. Most of the personal computer operating systems, game consoles, laptops, printers, smart phones etc, supports Wi-Fi. With the help of Wi-Fi, devices can connect directly with each other. This is said to be peer-to -peer connection. In other words it is termed as wireless adhoc networks.

It is to be noted that even digital cameras can transfer images trough wireless connection. Mobile computers can connect to Internet from Wi-Fi, which is also known a mobile adhoc networks(MANET). In Manet, the Wi-Fi concept is used and the data's are transferred from one device to another. Vic Hayes is known to be the father of Wi-Fi!! With the help of Wi-Fi there are many positives aspects taking pace in industries and business sites. One of the most advantage thing about Wi-Fi is that there is no usage of wires for client devices.

If there are places where the cable connection is not possible, Wi-Fi plays a vital role. Some of the disadvantages are it has got very limited range. A typical Wi-Fi home router using 802. 11b or 802.11g. It can be used for wide area networks.

TCP/IP

TCP/IP stands for Transmission Control Protocol and Internet Protocol. This type of internet protocol suite is generally used for internet and other networks. It is a set to communications protocols. TCP/IP model consists of four layers namely link layer, internet layer, transport layer and application layer. Application layer includes FTP, HTTP, SMTP, POP RTP et. Trasport layer includes TCP,UDP, ECN etc. Internet layer includes IP, IGMP,ICMP etc. Link layer includes ARP,NDP, OSPF etc.

It uses encapsulation to provide babstraction of protocols abd services in which the entire concept of layers depends. Most of the operating systems use TCP/IP model. Most of the computer networking use TCP/IP currently. Kurose uses four layers, Forouzan uses five layers which includes apllication, transport, network, datalink and physical layer. Cisco academy uses four layers of TCP/IP.

Broadband

The term broadband are generally used in telecommunications, its all about signaling methods. For our Internet purpose, we use broadband way of connection. It is a wide range of frequency that are divided in to channels or frequency bins. We use broadband in data communications, in DSL , in Ethernet, in power line communication, in video and many more. Related to broadband, there is narrow band and full service broadband too.

Most of the digital subscriber line services use broadband, through which the digital information are sent over a high bandwidth channel on a single pair of wires. It is also used for transmission. Multiple data are sent simultaneously to increase the effective rate of transmission of data. Even a television antenna can be broadband which helps it to receive more number of channels. Even a telephone line can be of broadband way of connection. Broadband plays a vital role in telecommunications, as it is used for many purpose that makes things easy and comfortable.

Computers

We all know how much the computers are useful to humankind in day today life. It is almost like, if there is no computers, there will not be any works in current scenario. Let us know how it entered this world. We all know with the help of computers, one can store , retrieve and process data as quickly as possible. The basic idea of computing was developed in the early 1200's by Moslem Cleric. He was the one who solved problems with a series of written procedures. It is to be noted that in 1640's mechanical calculators are manufactured.

Its Blaise Pascal who invented the first commercial calculator. After the first mass produced calculator in the year 1820, The great Charles Babbage begins his lifelong quest for a progrmmable machine. Exactly twelve years later, George Boole wrote the laws of thought(1854) and he was recognized as the father of computer science. Charles Babbage invented the mechanical computing machine called the analytical engine.

Modem

It is a combination of modulator and demodulator. The basic purpose of a modem is to produce a signal that can be transmitted easily and should decode to produce the original data. Modems transmit analog signals.

We all know modems are most probably used for internet connections. For this purpose, the cable modems and ADSL modems are used. There are narrow band and phone-line dialup modems. Some of the radio modems like WiFi and WiMax and mobile modems and routers are also used for various purpose. For current scenario, mostly standard modems are used, which has two functional parts.

One of it will generate the signals by analog section and another one is used for set up and control by digital section. Modems that exits currently are well advanced with increasing speeds. Mostly for a laptop, a 2400 bit/s modem are used. It is to be known that ISA mosems are manufactured to conform to the V.34 protocol.