An agent is a pre-configured query which you can use to check for interesting new items when they arrive in the system. You can run it again manually or automatically to find new items which have arrived since it was last checked, and you can ask it to send an e-mail message (an alert) to a specified e-mail address whenever new items arrive. Agents are particularly useful when you regularly search for the same information (for example, about a specific company).
Agents come in two types: