On the Internet, an agent (also called an intelligent agent ) is a program that gathers information or performs some other service without your immediate presence and on some regular schedule. Typically, an agent program, using parameters you have provided, searches all or some part of the Internet, gathers information you're interested in, and presents it to you on a daily or other periodic basis.
An example of an agent is Infogate, which alerts you about news on specified topics of interest. A number of similar agents compare shopping prices and bring the news back to the user. Other types of agents include specific site watchers that tell you when the site has been updated or look for other events and analyst agents that not only gather but organize and interpret information for you.