The Application Kit is a framework containing all the objects you need to implement your graphical, event-driven user interface: windows, panels, buttons, menus, scrollers, and text fields. The Application Kit handles all the details for you as it efficiently draws on the screen, communicates with hardware devices and screen buffers, clears areas of the screen before drawing, and clips views.

You also have the choice at which level you use the Application Kit:

-   Use Interface Builder to create connections from user interface objects to your application objects.

-    Control the user interface programmatically, which requires more familiarity with AppKit classes and protocols.

-    Implement your own objects by subclassing NSView or other classes.