The Physical Model
The Physical or Deployment Model provides a detailed model of the way components will be deployed across the system infrastructure. It details network capabilities, server specifications, hardware requirements and other information related to deploying the proposed system.
The physical model shows where and how system components will be deployed. It is a specific map of the physical layout of the system. A deployment diagram illustrates the physical deployment of the system into a production (or test) environment. It shows where components will be located, on what servers, machines or hardware. It may illustrate network links, LAN bandwidth & etc.
A node is used to depict any server, workstation or other host hardware used to deploy components into the production environment. You may also specify the links between nodes and assign stereotypes (such as TCP/IP) and requirements to them. Nodes may also have performance characteristics, minimum hardware standards, operating system levels & etc. documented. The screen below illustrates the common properties you can set for a node.