Basic Architectural Concepts
The SAP R/3 system uses some widely known terms to which SAP gives specific meanings. This section includes some of those terms, needed for a clear understanding of the architecture of SAP Basis, now the SAP Web Application Server.
Generally, a transaction is an operation that lets a user make changes to a database. The overall SAP R/3 system must be seen as a business transaction processing system. This means that the whole data flow that runs across application modules is executed using transactions.
In the SAP systems, a transaction is a sequence of related steps. These logically related steps, known as dialog steps, are screens in which data are introduced, causing the generation of other events. ...