Tables can be defined independently of the database in the ABAP Dictionary. The fields of the table are defined with their (database-independent) data types and lengths.
When the table is activated, a physical table definition is created in the database for the table definition stored in the ABAP Dictionary. The table definition is translated from the ABAP Dictionary to a definition of the particular database.
A table definition in the ABAP Dictionary contains the following components:
The customer can modify SAP tables withappend structures and customizing includes. This kind of modification ensures that the customer enhancements are automatically merged with the new versions of the SAP tables when there is a release upgrade.
See also:Creating Tables Making Changes to Tables