Composite structure is a diagram, which represents the internal structure of structured classifiers by using parts, ports, and connectors. A structured classifier defines the implementation of a classifier and can include a class, a component, or a deployment node. It shows the internal details of a classifier and to describe the objects and roles that work together to perform the behavior of the containing classifier. It is a set of interconnected elements that collaborate at runtime to achieve some purpose. Each element has some defined role in the collaboration.