Think of a job as a folder that contains all the elements of the job you're producing. The Overview has the description of the job as well as the contact information and is where you can link to external documents that are associated with the job. The Estimate section has the bid for the job along with all the revisions. The Production section is a workspace to produce the job, and finally the Invoice is what you send to the client to get paid. All these elements make up the job.