A job order refers to the job posting or requisition. In Fieldglass, once a candidate has been selected and the terms of the assignment (e.g., start and end dates, hourly billing rate) have been mutually agreed to by the hiring manager and the supplier, the Job Order becomes a Work Order.
A work order is specific to that worker and that job. It includes an agreed-upon hourly billing rate, cost allocation, length of assignment, and other elements used to track that specific combination of person and position. Revisions to the assignment, such as extension of the assignment or changes in the costing, require a work order revision.