special kinds of scripts always stored in system.agents table actually it is an instance of a running script runs in background

Agents are computational entities which analyze user activities and user products. They are not activitated explicitly by the user but act on their own dependent of changes in the computational environment. Examples: critics, expectation agents

Self contained processes that run in the background on a client or server and that perform useful functions for a specific user/owner. Agents may monitor exceptions based on criteria or execute automated tasks.

An "agent," or user agent, is a web browser or other program used to access your web server. Most user agents are web browsers such as Microsoft Internet Explorer and Netscape Navigator, but a significant number are automated Internet-indexing programs, such as Altavista.

See Main Definition: automated document classification Usage: "agents" was a very hot marketing term in the 1990s; when search engine vendors talked about agents what they were typically referring to was their automated document classification products ("agents" sounded cooler)