By canceling a job or job set in the list view of the Jobs folder, you prevent the job or the jobs in the job set from being run on the host:
Note that canceling a job may have no effect if the job is just about to start on the host.
Note:
To cancel a job or job set in the Jobs folder, select the jobs folder in the resource tree to display all jobs and job sets in the list view. Then select the job or job set in the list view and click File --> Cancel on the menu.