An outlet is a property whose value you can set graphically in a nib file. You use outlets when your code needs to interact with objects in a nib file. You declare an outlet in the interface of a class, and you make a connection between the outlet and another object in the nib file. When the file is loaded, the connection is established.
The object containing an outlet is often a custom controller object such as a view controller. You define an outlet as a property with the type qualifier of
@property (weak) IBOutlet NSTextField *nameField;
You can make outlet connections between any objects that can be represented as instances in a nib file, even between two custom objects.