The Unified Modeling Language User Guide, 2nd Edition

Chapter 11. Interfaces, Types, and Roles

In this chapter

• Interfaces, types, roles, and realization

• Modeling the seams in a system

• Modeling static and dynamic types

• Making interfaces understandable and approachable

Interfaces define a line between the specification of what an abstraction does and the implementation of how that abstraction does it. An interface is a collection of operations that are used to specify a service of a class or a component.

You use interfaces to visualize, specify, construct, and document the seams within your system. Types and roles provide a mechanism for you to model the static and dynamic conformance of an abstraction to an interface in a specific context.

A well-structured interface provides a clear separation between the ...