bapi is indirect system call ?
can anyone explain this?
BAPI's are programming interface to access SAP Database from within SAP or other development platforms external to R/3 that support the Remote Function Call (RFC) protocol. The main objective of BAPI is to achieve integration between the R/3 System and external applications, legacy systems etc. This gives you the option to have non-SAP front-end for occasional users.
BAPI is like a Function module. BAPIs used for outbound processing.
Transaction code to list all BAPI's: BAPI
reward if useful..