Build Event Handlers are tasks which execute on the server (as opposed to Actions which run on the agents). They can be configured to respond to one or more Build Events which occur as the build progresses.
The following Event Handler types are available:
Build Event Handlers can be created within the Events step of the Configuration Wizard.
The name of the build event handler.
The run order.
Determines if the build event handler will be executed.
The type of build event handler.
The conditions which must all evaluate as true before the build event handler is executed.