Here’s a simple scenario.
Suppose you want managers and technical staff to be notified whenever a critical service called COREBUSINESS stops on a server.
You build a simple BizTalk application with a receive location configured with EventADAPTER that receives any events from that server relating to COREBUSINESS stopping. You add a send port to the application that emails an alert message to the managers and technical staff. You might also add some actions into the application to write the stoppage information to a database for later analysis or SLA negotiation.
Job done.