Data Dictionary: It is a collection of descriptions of the items or data objects in a data model for the profit of programmers and others who require referring to them. The first step in analyzing a system of objects with which users act together is to recognize each object and its relationship to other objects. This procedure is termed as data modeling and outcomes in a picture of object relationships. Subsequent to each and every data object or item is provided a descriptive name, its relationship is explained (or it becomes portion of some structure which implicitly explains relationship), the kind of data (like text or image or binary value) is explained, possible predefined values are listed, and a short textual description is given. This collection can be planned for reference into a book termed as data dictionary.