Job Control Language

Job Control Language (JCL) is a name for scripting languages used on IBM mainframe operating systems. It instructs the system on how to run a batch job or start a subsystem.^[1]

The purpose of JCL is to say which programs to run, using which files or devices ^[2] for input or output. It can indicate under what conditions to skip a step.

There are two distinct IBM Job Control languages:

one for the operating system lineage that begins with DOS/360 and whose latest member is z/VSE; and
the other for the lineage from OS/360 to z/OS, the latter now including JES extensions, Job Entry Control Language (JECL).

They share some basic syntax rules and a few basic concepts, but are otherwise very different.

Notes

↑ "Every job submitted for execution ... must include JCL statements" -- ibm.com
↑ and many more complex details, such as whether the file is to be retained or deleted, the maximum of disk space to which it can grow, the name of a tape to be pre-mounted

[1] "Every job submitted for execution ... must include JCL statements" -- ibm.com

[2] y more complex details, such as whether the file is to be retained or deleted, the maximum of disk space to which it can grow, the name of a tape to be pre-mounted

[1]

[2]