8. Events
An event is a signal that informs our app of a user interacting with the screen. Events collect all types of interactions that the user can perform, together with their associated information.
The Android system provides the information about all the events and each app specifies in its code which events it needs to process. For example, most applications will need to process button click events. More specific applications may need to track other types of events. For example, drawing applications must be aware of the path traced by fingers moving on the screen in order to draw a suitable shape.