A component diagram in UML is used to break down a large object-oriented system into smaller components to make it more manageable. It represents the physical view of a system, such as executables, files, libraries, and so on, that is contained within the node. A component diagram in UML is a collection of vertices and arcs that typically have components, interfaces, dependency, aggregation, constraint, generalization, association, and realization relationships. It may also include notes and conditions. A UML component diagram describes how physical components in a system are organized and wired together. Component diagrams are frequently used to help model implementation details and double-check that planned development covers every aspect of the system's required functions.