JOBLIB specifies a loadlib that searched when looking for programs in the job.JCLLIB specifies the library to search in order to find the JCL frags specified in INCLUDE statements
jcllib: when job is submitted JCL will check the JCL syntax error is there or not inside a sys1.
proclib: if there is no error is being transferred to a output queue via conversion where jobs waiting for execution
joblib: if a job is submitted in JCL if a program get terminated during the execution of job time it will get get abend joblib is basically used to check whether job is there is not after at which step the program get terminated it will restart by using the syntax step proc.name
JOBLIB DD statement specifies the private library that the system needs to search to obtain the program named in each of the EXEC statements PGM parameters. Only if the program is not found in the private the system searches in the system libraries.
JCLLIB statement species the private library that the system needs to search to obtain (a) the procedures (PROCS) named in the EXEC statement (b) the Groups of JCL statements (called INCLUDE groups) named on any INCLUDE statements
