by Dinesh Thakur Category: Computer Terms

File Allocation Table (FAT). A data structure employed in the FILESYSTEMS of Microsoft's MS-DOS and Windows operating systems to locate individual files stored on hard and floppy disks. When a disk is FORMATTED it is divided up into many physical SECTORS of equal size grouped together into CLUSTERS. Whenever a new file is created, the file system allocates a number of these clusters to hold that file's data - the FAT is a table that contains the name of each file and the addresses of the clusters that it occupies. When a file is deleted, only its FAT entry, rather than the data itself, is erased, which is why UNDELETE utilities can usually recover the file.



 
by Dinesh Thakur Category: Computer Terms

An EGA is a video adapter for IBM-type personal computers. This means it has the electronic circuits your computer needs to display images on the screen. EGA stands for enhanced graphics adapter, but don't be fooled by the name: EGAS came out in about 1985, and what was "enhanced" then (compared to a CGA) is obsolete now. Yes, they still work, and if you get a computer that has one, don't throw the EGA board away.



 
by Dinesh Thakur Category: Computer Terms

A driver is a piece of software that tells the computer how to communicate with or operate another piece of hardware, such as a printer, scanner, or mouse.



 
by Dinesh Thakur Category: Computer Terms

A drive is the part of the computer that takes the disks or tapes you insert into the slot and spins them to make them work. You probably have at least two different kinds of drives in your system: floppy disk drives are the ones with the little slots where you insert floppy disks; the standard type of hard disk drive comes sealed inside a case, which in turn is stuck inside your computer or inside a separate box-you never even see the disk.



 
by Dinesh Thakur Category: Computer Terms

Information that is digital is information represented by numbers (digits) or more broadly, information that can be measured in discreet, exact values. The opposite term is analog, which describes information represented along a continuous range, where there are an infinite number of possible values. Trite as it may be, the best way to understand the difference between digital and analog is to compare a digital clock to a traditional round clock with hands.



 
by Dinesh Thakur Category: Computer Terms

A device driver is a piece of software designed for a particular device (printer, mouse, monitor, or what have you) and the particular application program or environment you're working with. The driver serves as a go between for the program (or environment) and the device, translating the software's desires into commands the device understands.



 
by Dinesh Thakur Category: Computer Terms

Device independent components work right no matter what model of device you use them with. For example, if the graphic file format in your publication is device independent, the results you see on paper will look about the same whether you print to an HP DeskJet, an Apple LaserWriter, or a high-resolution Linotronic image setter (the graphic will be printed at whatever resolution the printer uses).



 
by Dinesh Thakur Category: Computer Terms

A device just means any kind of component that's part of or attached to your computer. It can be located inside or outside the computer. A mouse, for example, is a device that sits outside the computer, while an internal disk drive (another device) is inside the computer. Devices need instructions on how to communicate with the printer or the rest of the computer, and sometimes those instructions aren't part of the computer's standard operating system.



 
by Dinesh Thakur Category: Computer Terms

Desktop publishing (DTP) is the process of creating printed documents that look professionally produced, using page layout software running on a personal computer, along with a high-quality, yet affordable, printer. To publish something with the traditional method, you would send typed or handwritten text to a typesetter, who would turn it into typeset text called "galleys," which took a couple of days. If there were corrections, it took another couple of days to get those back. If you didn't know how to layout the pages yourself, you'd take the galleys to a print shop, along with your art (illustrations and photographs).



 
by Dinesh Thakur Category: Computer Terms

The Desktop level is called a "level" because there is a hierarchy of different levels, kind of like different floors in a tall building. When you can actually see the Desktop, you can double-click to open folders and then you see that folder's window, right? That window is one level of the hierarchy. If you open another folder that is within that window, you go down one more level into the hierarchy. Well, the Desktop level is the very top of the hierarchy (or the root, some might say) because the first window (including the hard disk window) sits on the Desktop.

 
by Dinesh Thakur Category: Computer Terms

The Desktop is the background on your screen when you're using a Macintosh, Microsoft Windows, and similar graphical user interfaces. The idea is that this screen background is sort of like the top of your real desk, and your program windows are all lying on the desktop in a pile. Some programs may refer to their own "desktops." In this case, the desktop is what you see on the screen when the program is running but no document is open.

 
by Dinesh Thakur Category: Computer Terms

A bug is a problem in software or hardware; to debug is to diagnose and correct said problem. Software programs inevitably develop bugs due to mistakes in planning or simply from accidentally typing the wrong command. Before a program can run properly, all bugs have to be found and corrected. A debugger is an application developed for the specific purpose of finding these problems; it lets the programmer run the program one step at a time so that she can see exactly where the mistake occurs.

 
by Dinesh Thakur Category: Computer Terms

Sometimes, like in a school computer lab or in an office, you need to hook up several computers to one printer, or several computers need to connect to one file server, or maybe you have several devices (such as a scanner and a CD-ROM player) that you need to hook into one computer. Well, the only way to connect all these devices together, since there is only one port, or connecting place, on the back of the computer, is to connect each object (each device) to the next one in line, making a daisy chain.



 
by Dinesh Thakur Category: Computer Terms

Cylinder The set of all the TRACKS on a HARD DISK drive with multiple PLATTERS that may be read at the same time. All the tracks are the same distance from the central spindle, so they can be imagined as tracing a cylinder in space. The HEADS on all the platters move together in a parallel motion - a sequence of data stored within the same cylinder can be read at optimum speed without requiring any movement.

 
by Dinesh Thakur Category: Computer Terms

CMOS (Complementary Metal-Oxide Semiconductor) The most popular fabrication process for modern INTEGRATED CIRCUITS, which employs LOGIC GATES made out of complementary pairs of FIELD-EFFECT TRANSISTORS called the P-CHANNEL and N-CHANNEL respectively. The p-channel transistor is made within a well of n-type silicon, while the n-channel is made directly in the doped silicon SUBSTRATE. These two transistors are arranged so that a current flows only momentarily while the gate is switching, and none flows in its on or off states, which enormously reduces power consumption as compared with older BIPOLAR processes. It is this benign property that permits the phenomenal improvement in chip performance over recent decades that is referred to as MOORE'S LAW.

 
by Dinesh Thakur Category: Computer Terms

clock cycle The basic unit of timing within a computer system, consisting of one of the stream of regular pulses generated by the SYSTEM CLOCK. Most of a computer's components, in particular its processor, bus and memory systems, operate in strict step with the clock, so the number of clock cycles their various actions occupy is of crucial importance to a computer designer.



 
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.



 

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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.