Basics abt Computer Science

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.