DB2 is a relational database system. DB2 also allows multiple site database access to applications. IMS is more powerful - for mission critical online transaction processing. Time Sharing Option Permits users at display stations direct interaction with the system.
Users can then start application programs and perform system tasks.
Job Entry Subsystem Works with the MVS operating system to manage and control its workload. Virtual Telecommunications Access Method. VTAM provides network access to applications residing on the mainframe. Transmission Communication Protocol Allows users to communicate and interoperate with other systems. A powerful component that allows record-level sharing.