What is a data dictionary, what does it contain, and how is it used?

What will be an ideal response?

A data dictionary contains information about the structure of the database. Table 4-1 shows that there is a record in the dictionary describing each data element.The DBMS maintains the data dictionary, whose inputs include new or deleted data elements and changes in data element names, descriptions, or uses. Outputs include reports for programmers, designers, and users. These reports are used for system documentation, database design and implementation, and as part of the audit trail.