All storage obtained for your program by GETMAIN, STORAGE OBTAIN, or DSPSERV CREATE is automatically freed by the system when the job step terminates. Freeing storage in this manner requires no action on your part.
FREEMAIN or STORAGE RELEASE perform the equivalent of a page release for any resulting free page. The page is no longer available to the issuer. FREEMAIN can free a page that has been protected through the PGSER macro with the PROTECT option. DSPSERV DELETE performs the same action for a data space that FREEMAIN and STORAGE RELEASE do for address space virtual storage except that for a data space or hiperspace, all of the storage is released.