A Job is created when you run a data flow. A job tracks the run-time evidence of that data flow and any other processes or data flows that run as a consequence of that first data flow running. Thus, the job allows you to track CIC integrations from end to end, for example, from a partner, through processing in the Integration Engine, and all the way to your back-end system.
The Activity > Jobs screen shows a listing of all jobs run in CIC and allows you to filter the jobs down to the ones you are interested in. You can also drill into any job to get more details. In the Job Detail view, if the job failed, you can see where and why the job failed. Additionally, you can click on each step of the job to view payloads that were present and log activity that occurred at each step.
For more information, see Working with Jobs.