An interface is a specifier for the externally-visible operations of a class, component, or other classifiers (including subsystems) without a specification of the internal structure. Each interface often specifies only a limited part of the behavior of an actual class.
The set of interfaces realized by a classifier is its provided interfaces, which represent the obligations that instances of that classifier have to their clients. They describe the services that the instances of that classifier offer to their clients.
You can specify interface properties in the interface Specification window. In the same window, you can find the description of each property. Descriptions are presented in the description area of the Specification window.