An event is an expected action that occurs when a user interacts with available objects in the user interface. For example, the user expects an animation clip to play when the "Start" or "Play" button is pressed and to pause when the "Pause" button is pressed.
Writing a proper Windows GUI application entails creating all of the potential windows (forms) and objects (controls) that the user may interact with, determining all of the possible events that may occur, and creating a link between each potential event and the application code to handle the event. This concept is known as event-driven programming.
Writing and editing event procedures, therefore, is the process of determining the possible events for each form and control and then creating the links between the events and the application code handling the events.
