What is an Activity?

• An Activity is a single screen visible on the screen and has the capability to interact with the user.
• Application’s presentation layer. Every screen in your application will be an extension of the Activity class.
• Activities use Views to form graphical user interfaces that display information and respond to user actions.
• A view hierarchy is placed within an activity's window by the Activity.setContentView() method.
• In terms of desktop development, an Activity is equivalent to a Form.
• An application might consist of just one activity or, it may contain several.
• In an Application, usually one activity is made as a main activity, which will be placed in the launcher menu as an icon to start the application.