Summary

Two transaction programs use LU 6.2 to exchange data in a conversation. One, the client transaction program, is typically started by a user. The other, the server transaction program, can be started automatically to render a service to the client. A transaction program uses one of two APIs: APPC, or CPI-C, which have different styles and similar, but not identical, sets of services.

The conversation takes place over a session between two LUs. An LU represents a point at which a transaction program can access the SNA network. A session represents the connection between two LUs, without regard to their location or the distance between them.