What is Analysis phase ?

What is Analysis phase? Please describe that which things come under analysis phase?

In analysis phase after collecting / requirements information from users of the old system, designers analyze the requirements of the users and establish the procedure to meet those requirements. From the database perspective, in the analysis phase designers have to identify the facts or data that is required to be stored in order to fulfill the user's requirements. For this purpose they may use some CASE tools, like cross reference matrix. Generally, in the analysis phase, designers prepare a draft or initial database design that they ultimately finalize in the next phase, that is, the database design phase. So in short we can say, that DFDs are the input to the analysis phase. The initial design or a draft form of design (generally in entity-relationship data model) is the output of the analysis phase. After that in the design phase, you finalize the design.