First of all JOBLIB and JCLLIB are not part of the COBOL language - they are part of the Job Control Language (JCL). What have you read and where? What do you not understand as they are 2 compleely different things. Also, if you had searched the forum first you would have come across this link a few days ago.jcl/joblib-jcllib-steplib-t3964.html
Further, if you read every post, and not just your own, you would expand your knowledge and you would have gotten this answer days ago.
The problem I have is that people can explain things quickly but I can only comprehend slowly.