CHKP (basic) call will be used to recovery purpose. It just collects checkpoint id and writes to checkpoint file. When checkpoint arrives, it commits all the work, and update the checkpoint file. This will work with both MPP and BMP.
XRST call. It must be the first call. It should only be used with CHKP(symbolic) call. It should be preceded by CHKP(symbolic) call. This is allowed in BMP and Batch applications. This call will have capability to retrieve the data stored by CHKP(symbolic) call.Read here for usage.
CHKP(Symbolic) call will be used to store 7 areas of the program. When checkpoint arrives, it commits the work, and updates checkpoint file. It works with XRST call. It is allowed in Batch and BMP applications.