System Modeling :-

• System modeling is the process of developing abstract models of a system, with each model presenting a different view or perspective of that system.
• It is about representing a system using some kind of graphical notation, which is now almost always based on notations in the Unified Modeling Language (UML).
• Models help the analyst to understand the functionality of the system; they are used to communicate with customers.

Types Of Model :-

• Physical model : Physical models are the most explicit way in which to describe a system; they capture the hardware composition of a system in terms of the computers (and other devices, such as mobile phones) and their interconnecting networks.

• Architectural models : Architectural models describe a system in terms of the computational and communication tasks performed by its computational elements; the computational elements being individual computers or aggregates of them supported by appropriate network interconnections.

• Fundamental model : Fundamental models take an abstract perspective in order to examine individual aspects of a distributed system. In this chapter we introduce fundamental models that examine three important aspects of distributed systems: interaction models, which consider the structure and sequencing of the communication between the elements of the system; failure models, which consider the ways in which a system may fail to operate correctly and; security models, which consider how the system is protected against attempts to interfere with its correct operation or to steal its data.