Running a procedure

This is another way of running a program with the EXEC statement.
A procedure is a set of JCL statement, usually multiple steps stored in a separate PDS.
This is useful if some common processing functionality is required by many users and scripts.
EXEC PROCNAME is the syntax for it, with the PROCNAME being the name of the file containing the procedure.

You can also use it as the PROCNAMEPROCNAME positional keyword

just like programs, procedures are searched for in default system libraries when referenced.