Component Diagram

C4 level 3 diagram decomposing a container into groups of related functionality (components) and their collaborations.

What is Component Diagram?

The Component diagram opens up one container and reveals the components inside — higher-level groupings of code (controllers, services, repositories, etc.) that have a single responsibility. Unlike a class diagram, a C4 Component is an abstraction, not necessarily a 1:1 mapping to a programming-language class.

Related terms

  • Container Diagram — C4 level 2 diagram showing the deployable/executable units (applications, services, databases) that make up a software system.
  • Code Diagram — C4 level 4 diagram showing the implementation-level details (classes, interfaces, functions) of a component.