by Dinesh Thakur Category: Computer Terms

CD-R (Compact Disc Recordable) AWRITE-ONCE version of the CD-ROM disc, which can be used to distribute and back up computer data or to copy music CDS. Though it follows the same data format and can be read in standard CDROM drives, CD-R employs quite a different physical storage process, based on an organic dye film that is selectively bleached by a laser beam, which explains the blue or green colour of the recording surface.



 
by Dinesh Thakur Category: Computer Terms

A microprocessor is a single chip that is the central processing unit, or the brains of a computer. To function as a complete computer, it also needs memory, a clock) and a power supply. Well, a computer on a chip has its own built-in clock and its own memory, so all it needs is a power supply to function. These tiny things are used in all kinds of things, from car parts to children's toys.



 
by Dinesh Thakur Category: Computer Terms

COMMAND.COM is the program that serves as the DOS command processor, or the DOS shell if you prefer. Like any operating system, DOS itself is simply software, albeit software that has a very special role in running your computer. Dos consists of a conglomeration of programs, utilities, and device drivers, but at its core are three key pieces of software. They must be present on the disk you use to start your computer, or the computer won't work. Of these three pieces of software, the only one you're likely to run across is COMMAND.COM-you'll see it in the list of files on your screen when you display the directory of that start-up disk, by typing DIR and pressing Enter. (The other two essential DOS files are hidden files, so you won't see them in the directory list.)



 
by Dinesh Thakur Category: Computer Terms

A cluster is the smallest single unit of the space on a disk (a hard disk or a floppy or even an optical disc) that your computer's operating system keeps track of separately. The operating system keeps systematic records of which clusters are occupied by each file stored on the disk (in DOS, this is called the file allocation table, or FAT). Clusters usually consist of more than one sector, a sector being the smallest unit of disk space that the computer can read data from or write data on. There are too many sectors on a hard disk to keep track of them all individually, so the operating system deals with them in groups called clusters instead.



 
by Dinesh Thakur Category: Computer Terms

Clock speed refers to how fast the system clock drives the computer's CPU (central processing unit, the chip that runs the computer) which determines how fast the system as a whole can process information internally. Clock speed is measured in megahertz; a speed of one megahertz (l MHZ) means the system clock is sending out its electric current one million times per second. The higher the clock speed of a computer, the faster the computer can operate, assuming all other factors are equal. However, clock speed isn't the only factor that determines your computer's overall performance, or even how fast the microprocessor (another term for the cpu) gets things done. Two different microprocessors may run at the same clock speed, and still take different amounts of time to finish a given job.



 
by Dinesh Thakur Category: Computer Terms

CD-ROM (pronounced "see-dee rom") stands for compact disk, read only memory. A NON-VOLATILE OPTICAL DISK STORAGE medium based on the same physical disk format as the audio Compact Disc (CD), developed by Philips and Sony. A CD-ROM actually looks just like the CDs we play music with. To use one with your computer, you need a CD-ROM player, also called a CD-ROM reader. A CD-ROM can hold up to about 600 megabytes of information, which is the equivalent of about 700 regular floppy disks. There are CD-ROMs that hold the entire works of Shakespeare, complete dictionaries, histories, images of the works in the Louvre, etc., etc., ete. You can search the CD for the particular information you want to work with, copy it, then paste it into your own documents on your hard disk to do with what you will. You can only read from a CD-ROM, though-you can't store information onto it. The biggest complaint about CD-ROMs is that they are relatively slow.



 
by Dinesh Thakur Category: Computer Terms

A card, or printed circuit board, also known as a board, is a piece of plastic with chips attached to it. Chips are the tiny little circuits that run the computer. You buy a card and stick it inside the computer box. You can get accelerator cards (boards) that make your computer run faster, video cards that give your computer more graphic capability, and clock cards and printer cards or whole computers on a card. They range in price depending on what they do, who makes them, and so on. For instance, an accelerator card can cost $300-$1500.



 
by Dinesh Thakur Category: Computer Terms

Boot Sector Virus: A computer VIRUS program that hides its code within the BOOT SECTOR of a FLOPPYDISK, so that the virus code is executed before the operating system itself has loaded, making countermeasures difficult to apply. Once loaded into memory, such a virus infects the boot sectors of any other floppy disk that is placed in the drive, hence ensuring its spread.



 
by Dinesh Thakur Category: Computer Terms

Boot Record: A set of crucial data written on the BOOTSECTOR of a HARDDISK or FLOPPYDISK that contains the information required by the INITIAL PROGRAM LOADER to locate a copy of the operating system on the disk and load it into memory. Damage to the boot record can prevent the computer from booting from that disk, and render the disk's other contents inaccessible; many disk repair utilities work by preserving and restoring backup copies of the boot record. Some types of VIRUS hide themselves within the boot record.



 
by Dinesh Thakur Category: Computer Terms

Bootstrap: To start a computer by loading its OPERATING SYSTEM from disk storage into memory. The name alludes to the seeming absurdity of trying to lift oneself off the floor by pulling on one's own bootstraps - since it is the operating system that enables a computer to read disks, then loading itself from disk would seem to be a similar impossibility. This paradox is resolved by the presence of a small program called the BOOTSTRAP LOADER, which resides permanently in the computer (stored in a ROM chip) and contains just sufficient code to read the rest of the operating system from disk. This process is informally called 'booting' or 'booting up' the computer.



 
by Dinesh Thakur Category: Computer Terms

Boot Sector The first sector on a FLOPPY DISK or HARDDISK formatted for the MS-DOS operating system, which records the number of HEADS,CYLINDERS and SECTORS per cylinder used on that disk. This information is needed by the disk controller to access data on the drive, and the boot sector is located at head 0, cylinder 0, sector 0, so the controller can always find it regardless of how the drive is formatted. Other operating systems such as UNIX also reserve a special sector for such initialization information, but it is typically in a different form, so one operating system can rarely boot from another's disk.



 
by Dinesh Thakur Category: Computer Terms

Boot Drive: The disk drive of a computer system from which the operating system is loaded when the computer is first started up. Many operating systems allow the identity of this drive to be altered: for example on IBM compatible pcs it is determined by a setting in the machine's BIOS parameter area.



 
by Dinesh Thakur Category: Computer Terms

Biometrics: The measurement of parts of a person's body, for example fingerprints, voice timbre or unique patterns in the iris of the eye, to identify the person for security purposes. Computers can now process such data sufficiently fast for biometric methods to be used in real time as keys to gain access to a system. For example, when a finger is placed on a scanning pad, the print is immediately compared with one stored in a database of authorized persons.



 
by Dinesh Thakur Category: Computer Terms

The B word. If something is wrong with a piece of software or hardware so that it stops working or destroys your data or just acts weird, the product is said to have a bug, or to be buggy. The term actually comes down to us from the real live crawling and flying bugs that used to get into those old giant-sized computers .

 
by Dinesh Thakur Category: Computer Terms

Bleed refers to any element on a page that is printed beyond the edge of the paper. Whenever you see anything (text, graphics, photographs) that is printed right up to the edge of the paper, it was actually printed onto larger paper over the margin guidelines, and the paper was trimmed.

 
by Dinesh Thakur Category: Computer Terms

Computer products go through extensive testing before they can be released to the unsuspecting and trusting public. When a product has passed the in-house testing stage (see alpha testing), it goes into beta testing, often just called beta. Beta versions of the product are sent out for beta testing to "normal" people who don't work for the company. (These people are then, logically, called beta testers or beta sites.) The beta testers work with the software or hardware in real-life situations and report back the things that go wrong or that need improvement.

 
by Dinesh Thakur Category: Computer Terms

Beep is the generic term for whatever sound a computer makes when it's trying to tell you something. If you press the wrong key or click on something you shouldn't, the computer will beep at you. Sometimes it beeps just to let you know that it has started or finished doing something (like copying a file). You can customize the beep sound in some computers. In particular, newer Macs and pcs with Windows 3.1 come with several sounds you can assign to various types of "events" in the system. Hundreds can be added, and you can even make your own sounds.



 
by Dinesh Thakur Category: Computer Terms

Bandwidth measures the amount of information that can flow between two points in a certain period of time. The "broader" the bandwidth, the faster the information flow. You can use the term to describe how quickly information moves from the hard disk into memory, or from the computer to an add-in board on the expansion bus, or from one modem to another across a telephone line. Depending on whether the transmission is digital or analog, the rate is measured in bits per second (bps) or in hertz (cycles per second).



 
by Dinesh Thakur Category: Computer Terms

Seek Time refers to how long it takes the read/ write head on a hard disk to move from one track to another. Technically, seek time is only one factor affecting "average" access time, and is not the same as access time. Because it sounds faster, certain disk vendors may try to woo you by quoting seek time specifications for their disks, but you should really base your comparisons on average access time.

 
by Dinesh Thakur Category: Computer Terms

Automated Teller Machine (ATM) Also called a CASH POINT, a combined computer terminal and cash dispensing machine connected via a WAN to a bank's central computers, that enables customers to make cash withdrawals and inspect account details from public sites such as streets, airports, shops and petrol stations. ATMs typically provide a small display screen that presents menus to the user, surrounded by a small number of buttons to make menu selections, and a numeric keypad for entering the customer's PIN number - the latter is checked against that stored on the customer's cash card, which must be inserted into a slot as a means of AUTHENTICATION.



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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