(1) A constant that notifies an application that some action is occurring, or has occurred. (2) In AppleScript an action an object can respond to. For example, a button click is an event that may result in execution of a clicked handler for the button that was clicked. Compare SMB/CIFS. (3) In Interface Builder, a type of connection that is specific to iPhone applications. Events represent different phases of user interaction for a control. Each event connection can also have multiple assigned target objects, each with its own distinct action message.