mohammadanis.jamadar

 Profile Answers by mohammadanis.jamadar Questions by mohammadanis.jamadar

• Oct 4th, 2011

 

JCL: is Job control Language.Through jcl we can decide what job has to be run what programs needs to be run.
JES: Job entry System : This will take care of the execution of the job . when a job is submitted it will allocate space for execution and will help in execution

rasheeed17

 Profile Answers by rasheeed17 

• Jan 19th, 2012

 

JCL:
JCL is a language,
We write JOBs in JCL laguage that is understood by Mainframe and job is executed, space allocations & other resource allocation is done according to the keywords specified by you in JCL.

JES:
JES is the MVS subsystem(part of your mainframe) that will handle/process/Schedule/allocates the JOBS/JCLs submitted by users

In short once you submit your JCL, JES will takes control of it, it will generates an JOB iD, validates your JCL for syntax errors , Shedule your job for execution, Allocates virtual memory for execution, allocates datasets specified iDD statementys etc ..... after completion of the execution it will deallocates the virtual memory of your JCL and finally purges the job from system