Difference between physical and abstract system?

Physical systems are tangible entities that may be static or dynamic in operation. For example, the physical parts of the computer center are the offices, desks, and chairs that facilitate operation of the computer. They can be seen and counted, they are static. In contrast, programmed computer is a dynamic system. Data, programs, output and application changes as the user's demand or the priority of the information requested changes.

Abstract systems are conceptual or nonphysical entities. They may be models-the abstract conceptualization of physical situations. A model is a representation of a real or a planned system. The use of models makes it easier for the analyst to visualize relationships in the system under study. The objective is to point out the significant element and the key interrelationships of a complex system.