In the z/OS® environment, clients have two robust IBM database management system (DBMS) products to choose from. DB2® for z/OS is a relational DBMS, and IMS™ DB is a hierarchic DBMS. Clients from many industries from all around the world use DB2 for z/OS and IMS to run their businesses on a daily basis.

The IMS product also provides a transaction management system, called IMS Transaction Manager (IMS TM), and a set of system services.