Glossary 267

L2 (level two) cache — Memory cache installed on the motherboard to help improve processing speed. It is slower than L1 cache and faster than main memory. See also cache, CPU cache, L1 cache.

LAN (local area network) — A group of computers or other devices dispersed over a relatively limited area and connected by a communications link that enables any device to interact with any other on the network.

liquid crystal display (LCD) — A type of display that uses a

liquid substance between two transparent electrode panels. When an electric current passes through the electrodes, the molecules in the liquid form a crystalline pattern that polarizes the light passing through it. A filter over the electrodes permits only non- polarized light to pass to the surface of the display, creating light and dark pixels.

load — To move information from a storage device (such as a hard disk) into memory for processing.

local area network — See LAN.

logical drive — A section of a disk that is recognized by the operating system as a separate disk drive. A system’s logical drives may differ from its physical drives. For example, a single hard disk drive may be partitioned into two or more logical drives.

M

megabyte (MB) — A unit of data equal to 1,048,576 bytes

 

 

(1024 x 1024 bytes). See also bytes.

 

memory — Typically refers to the computer’s main memory, where

 

programs are run and data is temporarily stored and processed.

 

Memory can be volatile and hold data temporarily, such as RAM,

 

or it can be nonvolatile and hold data permanently, such as ROM.

 

A computer’s main memory is RAM. See RAM, ROM.

 

microprocessor — See central processing unit (CPU).

 

MIDI (Musical Instrument Digital Interface) — A standard for

 

connecting musical instruments, synthesizers, and computers.

 

The MIDI standard provides a way of translating music into a

 

form computers can use, and vice versa.