What is an event?

Each object within an object model is defined by a property, a method, an event, or a combination of each. An event is a noun, and acts as something that takes place in an object. You write code for an object to respond to the act. Events are triggered by an action, such as a click, key press, or system timer.

For example, ActiveDocument.AfterSave event triggers an action in the Document object after it has been saved.