JCL or JOB Control Language is the scripting language of the mainframes. It is used to run programs on the Mainframe computer.
JCL is easy to learn. You can use the free MVS turnkey system to practice JCL. I have explained how to use the MVS system in my post: “Practice jcl using the free MVS Turnkey 3.8j system”
For basic JCL introduction you can visit my YouTube channel which has more details on the topic.