Wednesday, November 25, 2009

CD-RW (Compact Disc Re-Writable)

Stands for "Compact Disc Re-Writable." A CD-RW is a blank CD that can be written to by a CD burner. Unlike a CD-R (CD-Recordable), a CD-RW can be written to multiple times. The data burned on a CD-RW cannot be changed, but it can be erased. Therefore, you have to completely erase a CD-RW every time you want to change the files or add new data. While it may be somewhat inconvenient, this capability makes CD-RWs a good choice for making frequent backups. However, because CD-RWs can be erased, they don't store data reliably for as long as CD-Rs do. Therefore, you should use regular CD-Rs for long-term backups.

CD-R (Compact Disc Recordable)

Stands for "Compact Disc Recordable." CD-R discs are blank CDs that can record data written by a CD burner. The word "recordable" is used because CD-Rs are often used to record audio, which can be played back by most CD players. However, many other kinds of data can also be written to a CD-R, so the discs are also referred to as "writable CDs."

The data burned onto a CD-R disc is permanent, meaning it can not be altered or erased like the data on a hard drive. Typically, once a CD has been burned, it will not be able to record any more data. Some CD burning programs can record data as "sessions," allowing a disc to be written to mulitple times until it is full. Each session creates a new partition on the disc, meaning a computer will read a disc with multiple sessions as multiple discs. CD-RWs, on the other hand, can be erased and completely re-recorded. Like CDs, the data on CD-RWs cannot be altered, meaning the disc has to be completely erased each time you want to add new data.

CD (Compact Disc)


Stands for "Compact Disc." CDs are circular discs that are 4.75 in (12 cm) in diameter. The CD standard was proposed by Sony and Philips in 1980 and the technology was introduced to the U.S. market in 1983. CDs can hold up to 700 MB of data or 80 minutes of audio. The data on a CD is stored as small notches on the disc and is read by a laser from an optical drive. The drives translate the notches (which represent 1's and 0's) into usable data.

The first CDs were audio CDs, which eventually replaced audio tapes (which earlier replaced records). Audio CDs have the advantage of allowing the user to jump to different places on the disc. CDs can also be listened to an unlimited number of times without losing quality. Audio tapes can start to lose quality after listening to them as few as ten times. This is because the laser that reads the data on a CD doesn't put pressure on the disc, whereas the playheads on a tape deck slowly wear away the magnetic strip on the tape.

In 1985, CD-ROMs hit the computer market. Because they could store far more information than floppy discs (700 MB compared to 1.4 MB), CDs soon became the most common software format. In 1988, the CD-R (CD-Recordable) technology was introduced, allowing computer users to burn their own CDs. However, this technology did not become mainstream until the late 1990s. A smaller 3" CD, called "CD-3" is also available and is readable by most tray-loading CD-ROM drives.

DVD+RW (Digital Versatile Disk Rewritable)

Stands for "Digital Versatile Disk Rewritable." A DVD+RW is like a DVD+R, but can be erased and rewritten. DVD+RWs must be completely erased in order for new data to be added. DVD+RW discs can hold 4.7GB of data and do not come in double-sided or double-layer versions like DVD+Rs do. Still, 4.7GB of data is a lot of storage space. Combined with their ability to be re-recorded, DVD+RWs are a great choice for making frequent backups of your data. To record data onto a DVD+RW disc, you'll need a DVD burner that supports the DVD+RW format.

DVD+R (Digital Versatile Disc Recordable)

Stands for "Digital Versatile Disc Recordable." DVD+R discs look the same as regular DVDs, but can be used to record data. Single-sided, single-layer DVD+R discs can store 4.7GB of data, while double-layer discs can store 8.5GB and double-sided DVD-Rs can store 9.4GB. The DVD+R format is not quite as common as the DVD-R format, but is still supported by most current DVD players and DVD-ROM drives. Drives that can read both DVD+R and DVD-R discs are often referred to as DVD?R drives.

DVD (Digital Versatile Disc)



Stands for "Digital Versatile Disc." It can also stand for "Digital Video Disc," but with the mulitple uses of DVDs, the term "Digital Versatile Disc" is more correct. Yep, the technology naming people just love to confuse us. A DVD is a high-capacity optical disc that looks like a CD, but can store much more information. While a CD can store 650 to 700 MB of data, a single-layer, single-sided DVD can store 4.7 GB of data. This enables massive computer applications and full-length movies to be stored on a single DVD.

The advanced DVD formats are even more amazing. There is a two-layer standard that doubles the single-sided capacity to 8.5 GB. These disks can also be double-sided, ramping up the maximum storage on a single disc to 17 GB. That's 26 times more data than a CD can hold! To be able to read DVDs in your computer you'll need a DVD-ROM drive. Fortunately, DVD players can also read CDs. To play DVD movies on your computer, you'll need to have a graphics card with a DVD-decoder, which most computers now have.

CD-ROM (Compact Disc Read-Only Memory)



Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannot altered or erased. Because of this feature and their large capacity, CD-ROMs are a great media format for retail software. The first CD-ROMs could hold about 600 MB of data, but now they can hold up to 700 MB. CD-ROMs share the same technology as audio CDs, but they are formatted differently, allowing them to store many types of data.

Chipset

A chipset describes the architecture of an integrated circuit. This includes the layout of the circuitry, the components used within the circuit, and the functionality of the circuit board. For example, the chipset of a modem card is much much different than the chipset of a computer's CPU.

Processors themselves also have different chipsets. For example, A PowerPC processor, which uses RISC architecture, will have a much different chipset than an Intel processor that uses CISC technology. Even a Pentium II and Pentium III have slightly different chipsets, though they are both made by Intel. Regardless of what chipset a circuit uses, the important thing is that it works with other components inside the computer. Therefore, whenever you upgrade your computer's hardware, make sure you buy components that are compatible with the chipsets in your machine.

Computer "Chip" or "CPU"



Technically speaking, a computer chip is a piece of silicon with an electonic circuit embedded in it. However, the word "chip" is often used as a slang term that refers to various components inside a computer. It typically describes an integrated circuit, or IC, such as a central processor or a graphics chip, but may also refer to other components such as a memory module.

While "chip" is a somewhat ambiguous term, it should not be confused with the term "card." For example, a laptop might have a graphics chip embedded in the motherboard, while a desktop computer may contain a graphics card connected to a PCI or AGP slot. A graphics card may contain a chip, but the chip cannot contain a card. Similarly, a CPU may contain a chip (the processor), but it may also contain several other components. Therefore, the term "chip" can be used to refer to specific components, but should not be used describe multiple components that are grouped together.

SMPS (switched-mode power supply )



A switched-mode power supply (also switching-mode power supply, SMPS, or simply switcher) is an electronic power supply unit (PSU) that incorporates a switching regulator in order to provide the required output voltage.Switched mode power supplies or SMPS act as DC to DC converters.The switched mode power supply act as a DC to DC converter first rectifes an AC input voltage converts it to DC and depending upon the design considerations chosen, chops this DC in a "chopper" and converts it to a higher or lower level of DC or perhaps both a higher AND lower level of DC

Thursday, November 19, 2009

Floppy Disk


A floppy disk is a data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell.

Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be confused with "fixed disk drive", which is another term for a (nonremovable) type of hard disk drive. Invented by IBM, floppy disks in 8-inch (200 mm), 5¼-inch (133.35 mm), and 3½-inch (90 mm) formats enjoyed many years as a popular and ubiquitous form of data storage and exchange, from the mid-1970s to the late 1990s. While floppy disk drives still have some limited uses, especially with legacy industrial computer equipment,[2] they have now been largely superseded by USB flash drives, external hard disk drives, CDs, DVDs, and memory cards.

Floppy Drive


Short for floppy disk drive (FDD), a disk drive that can read and write to floppy disks.

Hard Disk


When you save data or install programs on your computer, the information is typically written to your hard disk. The hard disk is a spindle of magnetic disks, called platters, that record and store information. Because the data is stored magnetically, information recorded to the hard disk remains intact after you turn your computer off. This is an important distinction between the hard disk and RAM, or memory, which is reset when the computer's power is turned off.

The hard disk is housed inside the hard drive, which reads and writes data to the disk. The hard drive also transmits data back and forth between the CPU and the disk. When you save data on your hard disk, the hard drive has to write thousands, if not millions, of ones and zeros to the hard disk. It is an amazing process to think about, but may also be a good incentive to keep a backup of your data.

Motherboard


The motherboard is the main circuit board of your computer and is also known as the mainboard or logic board. If you ever open your computer, the biggest piece of silicon you see is the motherboard. Attached to the motherboard, you'll find the CPU, ROM, memory RAM expansion slots, PCI slots, and USB ports. It also includes controllers for devices like the hard drive, DVD drive, keyboard, and mouse. Basically, the motherboard is what makes everything in your computer work together.

Each motherboard has a collection of chips and controllers known as the chipset. When new motherboards are developed, they often use new chipsets. The good news is that these boards are typically more efficient and faster than their predecessors. The bad news is that older components often do not work with new chipsets. Of course, if you are planning on upgrading multiple components, it may be more cost-effective to just buy a new computer.

UPS "Uninterruptible Power Supply."


Stands for "Uninterruptible Power Supply." In the technology world, UPS is more than just a brown shipping company. It is also a type of power supply that uses battery backup to maintain power during unexpected power outages.

A typical consumer UPS is a surge protector that contains a high-capacity rechargeable battery. Smaller UPS devices look like bulky power strips, while larger ones may stand upright and look almost like small computers. Many businesses use uninterruptible power supplies to keep their equipment running in case of a power failure. While a UPS may only keep a computer running for 15 minutes after the power is lost, it is usually sufficient time to save all necessary documents and properly shut down the computer. That extra time can be invaluable to someone who is working on an important document or project that has not been recently saved.

Because UPS devices run the power through a battery, they have a limit on the wattage load they can support. The maximum power load limit is often included in the name of the UPS, followed by the letters "VA." For example, the APC (American Power Conversion) Battery Backup 750VA has a load limit of 750VA. However, the maximum wattage a UPS supports is typically 60% of the VA number. So the 750VA UPS supports a maximum of 450 watts for connected devices. It is important to check how many total watts your computer setup uses before buying a UPS to make sure you get one with enough wattage so you don't overload it.

Monitor


The term "monitor" is often used synonymously with "computer screen" or "display." The monitor displays the computer's user interface and open programs, allowing the user to interact with the computer, typically using the keyboard and mouse.

Older computer monitors were built using cathode ray tubes (CRTs), which made them rather heavy and caused them to take up a lot of desk space. Most modern monitors are built using LCD technology and are commonly referred to as flat screen displays. These thin monitors take up much less space than the older CRT displays. This means people with LCD monitors have more desk space to clutter up with stacks of papers, pens, and other objects.

"Monitor" can also be used as a verb. A network administrator may monitor network traffic, which means he watches the traffic to make sure the bandwidth usage is within a certain limit and checks to see what external sources may be attempting to access the network. Software programs may monitor the system's CPU performance as well as RAM and hard disk usage.

Finally, monitors also refer to speakers used for monitoring sound. Audio engineers typically use "studio monitors" to listen to recordings. These high-end speakers allow the engineers to accurately mix and master audio tracks. So a sound mixer could be monitoring a recording visually using a computer monitor, while monitoring the sound using audio monitors at the same. As you can tell, "monitor" serves as a rather multipurpose word.

Keyboard


As the name implies, a keyboard is basically a board of keys. Along with the mouse, the keyboard is one of the primary input devices used with a computer. The keyboard's design comes from the original typewriter keyboards, which arranged letters and numbers in a way that prevented the type-bars from getting jammed when typing quickly. This keyboard layout is known as the QWERTY design, which gets its name from the first six letters across in the upper-left-hand corner of the keyboard.

While the design of computer keyboards may have come from typewriters, today's keyboards have many other keys as well. Modifier keys, such as Control, Alt/Option, and Command (Mac) or the Windows key (Windows) can be used in conjunction with other keys as "shortcuts" to perform certain operations. For example, pressing Command-S (Mac), or Control-S (Windows) typically saves a document or project you are working on. Most of today's computer keyboards also have a row of function keys (F1 through F16) along the top of the keyboard, arrow keys arranged in an upside-down T, and a numeric keypad on the right-hand side. Some keyboards have even more buttons, allowing you to change the system volume, eject a CD, or open programs such as your e-mail or Web browser.

Mouse


The mouse is an input device designed to manipulate objects on the computer screen.

While most people don't want to see a mouse running around in their home, they typically don't have a problem seeing one sitting by their computer. This is because, along with the keyboard, the mouse is one of the primary input devices used with today's computers. The name comes from the small shape of the mouse, which you can move quickly back and forth on the mouse pad, and the cord, which represents the mouse's tail. Of course, if you are using a wireless mouse, the analogy does not work so well.

All mice have at least one button, though most mice have two or three. Some also have additional buttons on the sides, which can be assigned to different commands. Most mice also have a scroll-wheel, which lets you scroll up and down documents and Web pages by just rolling the wheel with your index finger.

Early mice tracked movement using a ball in the bottom of the mouse. This "mouse ball" pushed against different rollers as it moved, measuring the mouse's speed and direction. However, now most mice use optical technology, which uses a beam of light to track the mouse's motion. Optical mice are more accurate than roller-based mice and they have the added bonus of not getting dirty inside.

Wednesday, November 18, 2009

what if CUP.

Stands for "Central Processing Unit." This is the pretty much the brain of your computer. It processes everything from basic instructions to complex functions. Any time something needs to be computed, it gets sent to the CPU. Every day, it's compute this, compute that -- you'd think the CPU would need a break after awhile. But no -- it just keeps on processing. The CPU can also be referred to simply as the "processor."

What is the full form of C.O.M.P.U.T.E.R ?

C = Commonly
O = Operating
M = Machine
P = Particularly
U = Used for
T = Technical
E = Educational
R = Research.

Computer

Technically, a computer is a programmable machine. This means it can execute a programmed list of instructions and respond to new instructions that it is given. Today, however, the term is most often used to refer to the desktop and laptop computers that most people use. When referring to a desktop model, the term "computer" technically only refers to the computer itself -- not the monitor, keyboard, and mouse. Still, it is acceptable to refer to everything together as the computer. If you want to be really technical, the box that holds the computer is called the "system unit."Some of the major parts of a personal computer (or PC) include the motherboard, CPU, memory (or RAM), hard drive, and video card. While personal computers are by far the most common type of computers today, there are several other types of computers. For example, a "minicomputer" is a powerful computer that can support many users at once. A "mainframe" is a large, high-powered computer that can perform billions of calculations from multiple sources at one time. Finally, a "supercomputer" is a machine that can process billions of instructions a second and is used to calculate extremely complex calculations.