Logical design is “SOFTWARE setup” or how the system functions using each workstation,server, router based on the “useage” of each device within the system.

Physical design – is the HARDWARE layout, where cables are routed, where routers, servers, and workstations are located within a building. I has to include all the hardware needed. Patch panels end connections switch location, router location, server placement, etc.

Using “software” and “hardware” is usually easier to picture in the mind than “logical” and “physical” .

Here is a good paper used in real world
http://www.terarecon.com/downloads/news/casestudy_vanooijen_aquariusandpacs.pdf