SAP Work Processes

Work Process Type	Description
Dialog	D: Processes real-time information in the foreground.
Background	B: Background processing for long-running processes, reports, and batch jobs.
Synchronous Update	V1: Processes immediate updates to the database.
Asynchronous Update	V2: Processes updates to the database on a lower priority than V1 (that is, when time permits).
Enqueue	E: Manages database locks.
Message	M: Manages communication between application servers.
Spool	S: Manages print jobs (the print spool).
Gateway	G: Communicates with other SAP and non-SAP systems.