Editing Job Control Language (section)

==Terminology==
Certain words or phrases used in conjunction to JCL are specific to IBM mainframe technology.
* Dataset: a "dataset" is a file; it can be temporary or permanent, and located on a disk drive, tape storage, or other device.<ref>Ashley and Fernandez, ''Job Control Language'', p. 5.</ref><ref>McQuillen, ''System/360–370 Assembler Language'', pp. 385–386.</ref>
* Member: a "member" of a partitioned dataset (PDS) is an individual dataset within a PDS. A member can be accessed by specifying the name of the PDS with the member name in parentheses. For example, the system macro GETMAIN in SYS1.MACLIB can be referenced as SYS1.MACLIB(GETMAIN).<ref name="mcq-pds">McQuillen, ''System/360–370 Assembler Language'', pp. 288–289, 400.</ref> 
* Partitioned dataset: a "partitioned dataset" or PDS is collection of members, or archive. Partitioned datasets are commonly used to store textual data such as source code, assembler macros (SYS1.MACLIB), system configuration (SYS1.PARMLIB), reusable JCL procedures (SYS1.PROCLIB), etc. As such, they have something in common with archive files (ZIP, TAR, etc) and with directories in other operating systems. They are also used to store binary code (load modules or program objects); in that guise, they are roughly analogous to [[ar (Unix)|ar-based static libraries]] in Unix-based systems. As with most such structures, a member, once stored, cannot be updated; the member must be deleted and replaced, such as with the [[IEBUPDTE]] utility.<ref name="mcq-pds"/> Since the 1989 release of MVS DFP 3.2, PDSEs (Partitioned Data Set Extended) have existed as an improved version of PDS;<ref>{{Cite web |last=Lewis |first=Cecilia |date=August 8, 2011 |title=What We've Done for You Lately With PDSE |url=https://share.confex.com/share/117/webprogram/Handout/Session9939/SHARE%209939%20PDSE%20v1.pdf |access-date=2023-03-03 |website=SHARE in Orlando }}</ref> from the user or application programmer viewpoint, they are largely unchanged (save the removal of some obscure legacy features), but their internal implementation is very different.
* USS: Unix system services, a complete Unix environment running as part of the MVS base control program, and allowing Unix files, scripts, tasks, and programs to run on a mainframe in a fully POSIX compliant Unix environment without virtualization.