AGP
Accelerated Graphics Port is a type of expansion card slot on the mother board that is optimized to work with high performance video cards. They enable better viewing of 3D graphics and full motion video on your display.
BIOS
Basic Input Output System is code used when a PC first starts up. It contains configuration information about all the Input and Output devices in the PC so that the processor chip knows how to connect to and work with them.
BIT
This is binary digit and is the smallest piece of information a computer uses. A bit is always in one of two states, either 0 or 1, except for the tiny instant of time required to switch from one state to the other.
BYTE
A byte is eight bits. The data and instructions (code) that a CPU uses are coded into bytes. For example capital letter 'A' in ASCII (PC) code is byte 0100 0001. A lower case 'a' is byte 0110 0001.
BROWSER
Software on a computer used to request and display web pages from a Server.
CABLE MODEM
A type of modem that provides very high speed access to the Internet over the same cable that your cable TV service uses. Rates are asymmetric. This means that downloads are much faster than uploads. Typical download rates are 2 to 3 Mbps and uploads are in the 500Kbs range. This is blazing speed compared to a 56Kbps dial-up modem.
CACHE
Cache is a small fast SRAM type of memory. It prevents CPU slowdown, which happens when the CPU has to wait on slower devices like RAM memory and the hard drive. There are two levels of cache.
Level 1 or L1 cache is a small fast memory located on the same chip as the CPU. When files are first requested by the CPU they are read into the CPU from the hard drive and written into the L1 cache at the same time. When the CPU needs data again it checks the L1 cache and if it finds it there it gets it instantly. If not, it looks successively in the L2 cache, RAM and finally the hard drive, each of which is a little slower in delivering the data the CPU has requested.
This little bit of time saved by cache hits may not seem significant, but keep in mind that millions of accesses can be performed in a second. Every cache hit shaves time off the data access. Every cache miss adds time to the access. Cache misses lower performance and cache hits raise it!
Because level 2 or L2 cache is located in chips on the motherboard or on the board that holds the CPU it takes a little longer to access than the L1 cache.
L2 cache is becoming more important as it grows in size and performance. The L1 cache is very small because it is on the same chip as the large CPU. Due to it's small size, chances are high that the CPU won't find the data it needs there. An L1 cache miss causes the CPU to look in the L2 cache for the data.
The long and short of all this - If the data the CPU needs is not found in the L1 cache or L2 cache, the CPU must to wait to get it from the RAM memory. And if it isn't in RAM, then the CPU goes on vacation for a number of milliseconds, which is a long time in the CPU world, while the data is retrieved from the hard drive.
CDD
Compact Disk Drive is a storage device that uses optics to read data from compact disks. CDDs that can read as well as write are very popular now.
CPU
The Central Processing Unit is a special chip that controls what happens in a PC. It fetches instructions and does high speed computations on data. It is somewhat like our brain in that it controls everything we do.
DIMM
Dual Inline Memory Module is a small printed circuit board that contains DRAM memory chips. When we say a PC has 256 MBytes of memory we are talking about the total capacity of all the DIMM modules installed in it.
Modern motherboard provide two to four sockets that accept DIMMs.
DOMAIN NAME
A unique name, formed with letters and numbers, that points to the actual numerical Internet address which locates a particular computer connected to the Internet. For instance, The Yahoo domain name points to Internet address 66.218.71.198.
So when you enter www.yahoo.com in your browser and click go, a special server called a domain name server intercepts and directs your request to the server located at address 66.218.71.198.
DRAM
Dynamic Random Access Memory is type of memory that must constantly be refreshed to retain it contents. It is used as the main memory in a PC and is packaged in DIMMs which plug into the motherboard.
DSL Modem
DSL stands Digital Subscriber Line. The DSL modem is a fairly new device, which allows high speed data to move between your PC and the telephone company on the same line that you use for your telephone calls. Yes. you can use your PC and talk over this line at the same time without interference!
How? Picture of a double-decker bridge with two levels. The traffic on the two levels does not interfere with each other even though it is the same bridge, right? Think of your phone call using the lower level and your PC using the upper level. Instead of being separated by different levels in space, the separation is done by your PC and voice each using a different carrier frequency, just like two different radio stations.
FAT16
FAT is the abbreviation for File Allocation Table. It is a table where the system keeps basic information for each file on your hard drive. The 16 indicates the number of bits used to address the hard drive. The largest partition FAT16 can access is 2MB. When used on a hard drive that is bigger than 2MB the drive space will be divided into a number of partitions.
For example a 10MB drive would be divided into five partitions of 2MB each. If the drive were the only one in the system the partitions would be called C:, D:, E:, F:, and G:.
FIREWIRE
Firewire also known as IEEE 1394 or iLink is a very fast serial bus that runs at 400 Mbps. It competes directly against USB 2.0. Transmit and Receive data are carried on two separately-shielded twisted pair transmission lines. There are two other, rarely used, wires that provide power to remote devices.
Many newer computers have Firewire ports that are used to connect them to very fast external devices.
FTP
File Transfer Protocol is the method used by computers to send and receive files over the Internet.
HTML
Hyper Text Markup Language is the coding that is used to format web pages on Servers so that Browsers can display them.
HTTP
Hyper Text Transport Protocol is used by browsers and servers to facilitate the transport of web pages across the Internet.
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