Port

A port is a UML construct, used on component diagrams, that defines a distinct point of interaction between a component and its environment. Rather than exposing a single, undifferentiated boundary, a component can declare several ports, each one grouping the specific interfaces – provided, required, or both – that are relevant to one particular collaboration.

Separating a component’s interaction points into ports lets a diagram show precisely which interfaces are needed to fulfil which role, and lets two components be wired together port-to-port through a connector, without either side needing to know anything about the other beyond the interfaces exposed at that port.