Joined: 20 Jan 2007 Posts: 684 Location: Hollywood
PSB- Program Specification Block. This is defined external to program and is required for IMS program.
For IMS DB program this has definition which tells what the program can operate and what segments/ fields the program can use.
For IMS DC program this has TP which is to read/write IO messages.
PCB - This is Program communication block which is defined in Linkage of COBOL program. (This can be in any language like Pl1 Easytrieve etc)
It has different PCB masks for each Database and TP which are defined in the PSB of the related program.
IMS COBOL Batch program can be executed via Batch JCL.
This explanation is in short, you can refer to manuals for further info.