- Native Users
- They are unsophisticated users who interact with the system by invoking one of the application program that have been written previously.
- Application Programmers
- They are computer professionals who write application programs.
Application programmers can choose from many tools to develop user interfaces.
- Sophisticated Users
- They interact with the system without writing programs. Instead they write their requests in a database query language.
- Specialized Users
- They are sophisticated users who write specialized database applications that do not fit in to the traditional data-processing frame work.