L1 cache - A memory cache that is built into the CPU chip. A fast transfer speed for a memory bus, the conduit between the CPU and main memory (DRAM), is 66MHz. The L1 cache is a small, fast memory area that works together with the L2 cache to provide the CPU much quicker access to important and frequently-used data than searching the main memory.

L2 cache - A collection of memory chips on the motherboard. The L2 cache is a static RAM secondary memory area that is slower than the L1 cache but faster than main memory. An L2 cache is typically 256KB or 512KB. Increasing a level 2 cache may speed up some applications and have no effect on others.

LAN {lan} [local area network] - A data communications network that is geographically limited allowing easy interconnection of terminals and computers within adjacent buildings.

laptop computer - A portable personal computer of a size suitable to rest comfortably on ones legs.

laser printer - A non-impact, high-resolution printer which uses a rotating disk to reflect laser beams onto the paper. Print resolution ranges between 300 and 600 dots per inch (dpi).

LCD {ell-cee-dee} (see "liquid crystal display")

LDAP - (See "Lightweight Directory Access Protocol")

leased-line - A phone line that is rented for exclusive 24-hour, 7-days-a-week use from your location to another location. The highest speed data connections require a leased line.

LED printer {ell-ee-dee} - A printer which is similar in operation to a laser printer, but where an array of light-emitting diodes (LEDs) is used in place of the laser.

Lightweight Directory Access Protocol (LDAP) - standard protocol for accessing directory services, such as corporate address books, across multiple platforms. You can set up your browser to access LDAP directories from the Address Book. You can also set up Mail & Newsgroups to use an LDAP directory for e-mail address autocompletion.

line noise - Extraneous characters that appear in a computer transmission because of electrical noise in the communications link, which may be caused by a poor connection, electrical storms, or other problems.

Links Toolbar - On the Windows Taskbar, it provides shortcuts to important Web sites so that you can open them without first opening the browser.

Linux - An open source implementation of UNIX created by Linus Torvalds, which runs on many different hardware platforms including Intel, Sparc, PowerPC, and Alpha Processors.

liquid crystal display (LCD) - A type of display used on laptop computers that are lighter and consume much less power than other displays. Liquid crystals are rod-shaped molecules that spiral when they are exposed to an electrical charge. Polarized light passing through the layer of liquid crystal cells is twisted along the spiral path of the molecules.

A feature included on most digital cameras, it allows the user to preview images immediately after a photo is taken. It is this single feature that persuades many to switch the digital cameras.

ListServ mailing lists - Mailing lists are e-mail-based discussion groups. Instead of being sent to a specific individual on the list, messages are sent to a ListServ address so it can be distributed to everyone who subscribes to the list.

load - Transfer program instructions or data from a disk into RAM.

local system - The computer you are using. (see "remote system")

Location Bar - field (and associated buttons) near the top of a browser window where you can type a URL or search terms.

logical block addressing [LBA] - A method used on PCs and compatibles to increase the size limit for a single hard disk from 528 megabytes to 8.4 gigabytes.

log in - The act of accessing a computer system, usually by typing a username and password on a terminal.

log-in - The account name used to access a computer system.

log off - To exit a network or remote system.

log out - 1. Disconnect from a network by typing logout, exit, quit, or a similar word. 2. Disconnect from a computer system.

lossless compression - Compression methods in which no data is lost. With lossless compression, a large file can be compressed to take up less space, and then decompressed without any loss of information.

lossy compression - A compression technique in which a file can be highly compacted, but some data is lost. Large files such as graphics, video, or audio files can be stored in a smaller amount of space than with lossless compression, but some loss of quality will result when the file is decompressed.

lost cluster - A cluster is "lost" when there is no file allocation table entry for it.

LPT {ell-pee-tee} - A computer's printer port.

lurker - A visitor to an online discussion who reads other people's postings but does not contribute. Lurking is a good way for a beginner to get familiar with a newsgroup or forum.