The three constructs in the following table are integral to modeling the base structure of capsule-based models:
| Construct | Description |
|---|---|
| Capsule part | A capsule is a complex, physical, possibly distributed,
architectural object that interacts with its surroundings through
one or more signal-based boundary objects called ports. A boundary
is an object that lies on the periphery of the system, but within
it. Capsules communicate with the outside world only through ports. Because the internal implementation of a capsule is hidden from the environment, capsules are highly reusable. |
| Port | A port is a physical part of the implementation of a capsule, which mediates the interaction of the capsule with the outside world. A port implements a specific interface that specifies which messages a port can receive or send. |
| Connector | A connector is a signal-based communication channel that connects two ports. |