The Event Map

The Event Map should be placed in an mxml file by itself and added to the Application file. Typically, an application will create many event types, so it is recommended to have several Event Maps, grouping related event types in each. For example, you may have an event map that handles all Login-related events (login check, logout, forgot password, login success, etc) and a different event map for all the event that relate to updating a user's information (user add, user delete, user update, etc).

The component that defines the event map should extend from EventMap.

Also see Where should the Event Map go?