Two concepts used to begin defining System requiremets

First we need to create models. I can define a model as a reflection of the actual system plan before it is built, can be done theoretically or physically.

In this case of System requirements we need to develop two types of System Models,

1)A logical Model- shows what the system is required to do without committing to any technology.

2)A physical Model-this shows how the system will actually be implemented.