Deployment diagrams in the Unified Modeling Language (UML) show how software and hardware elements are linked. Deployment diagrams are unique in the UML world because they can describe hardware. Deployment diagrams can be used for various purposes, all of which are related to hardware. Once you've determined the intention of your deployment diagram, you'll need to figure out what's inside. Nodes are the main components of any deployment diagram. These large 3D boxes represent the elements that deploy objects. The deployed things are those in boxes, such as stereotypes, artifacts, and components (an example of a component is shown below).
