A deployment diagram shows the physical relationships among software and hardware components in the delivered system. A deployment diagram is a good place to show how components and objects are routed and move around a distributed system.
Each node on a deployment diagram represents some kind of computational unitin most cases, a piece of hardware. The hardware may be a simple device or sensor, or it could be a mainframe.
Figure 10-1 shows a PC connected to a UNIX server through TCP/IP. Connections among nodes show the communication paths over which the system will interact.