Ports represent interaction points through which a Classifier communicates with its environment.

The Interfaces associated with a Port specify the nature of the interactions that can occur over it. The provided Interfaces of a Port characterize requests to the Classifier that its environment can make through this Port. The owning Classifier must offer the Features owned by the provided Interfaces.

The Port Provides (Realizes) Interface is drawn from a Port to an Interface. In the example below, the relationship is drawn from the Port on Wheel, to the Interface definition, Transmission.

The full example, combined with the Required Interface side, is: