The Composite Structure Diagram is a visual representation of a system's internal structure and its components. It shows the relationships between the components and how they interact with each other. It is used to model the structure of a system, and can be used to identify potential problems and design solutions. The
From Wikipedia
Composite structure diagram in the Unified Modeling Language (UML) is a type of static structure diagram that shows the internal structure of a class and the collaborations that this structure makes possible.