The user context is the data that is specifically assigned to an SAP user.
Whenever an SAP user starts a transaction (an ABAP program), the work process processing the request always requires the user context.
Each user can open up to six external sessions ( ).
You can configure the maximum number of external sessions with parameter rdisp/max_alt_modes, but we recommend that you do not change the default setting of six sessions.
The user context contains a user-specific area containing user and authorization data, and a session context for each external session (technical term: emode).
The following figure shows the structure of a user context.
Each external session can administrate from its side multiple internal sessions (technical term imode). This is not explained in detail in this documentation.
All user contexts are contained in a common resource, the SAP Extended Memory, which enables a fast context change.