Link Farm
A set of web pages that have been built for the sole purpose of increasing the number of incoming links to a web site. This is done in order to increase link popularity and search engine rankings. Link farms usually require a reciprocal link from sites seeking listings. Link farms are a known spam tactic and sites that participate in them are likely to be penalized or banned from the major search engines.

Link Popularity
The number of other related Web sites that link to your site. In terms of search engine positioning, quality links are more important than the number of links. Search engines are now nullifying or penalizing sites using some link farms and link exchanges such as FFA (Free For All) sites popular with mass search engine submission programs.

Link Rot
A colloquial expression referring to the tendency of hyperlinks to "decay" as their destination sites are purged from their host servers. Users experience "link rot" as hyperlinks that lead nowhere, or that prompt "Error 404: file not found" messages.

Linkage
Instructions that connect one program to another, providing continuity of executions between the programs

Listserv
Listservs are the most common kind of maillist.

Login
The act of entering in your credentials, usually username and password, to connect to a computer system or web site. Also the non-secret account name used to gain access to a computer system.