Managing Database Manager Operators 
The SAP DB database system differentiates between two main user classes:
Database Manager operators (DBM operators)
Database Users
When creating new database instances, you must first create the first user of each of these classes for each instance. These are the first Database Manager operator and the database system administrator (SYSDBA).
Each of these users then has the authorization to create additional users of the specified user classes.
See also:
User Manual: SAP DB ®
User Concept
Note that a Database Manager operator can only manage a database instance but cannot work with the database objects.
A database system administrator, on the other hand, can work with the database objects and also has the authorizations of the first Database Manager operator. He or she can also perform all Database Manager functions.