Here is a component diagram example. Component diagram shows components, provided and required interfaces, ports, and relationships between them. This type of diagrams is used in Component-Based Development (CBD) to describe systems with Service-Oriented Architecture (SOA).
The following nodes and edges are typically drawn in a component diagram: component, interface, provided interface, required interface, class, port, connector, artifact, component realization, dependency, usage. These major elements are shown on the picture here.