A data model is a representation of the data stored in your system. It shows how the data are related to each other and describes their attributes. It can be in the form of a diagram or a table.
The data model indicates the business rules that apply to the data. The model helps you identify data problems, such as missing or inconsistent information. In most projects, data is grouped together to create an overall model.
The model is also used to help analyze, present and plan project management processes. Thus, it helps to optimize project management.