A major difference between process costing and job-order costing is:

Costs are calculated at each step in a job-order system while only calculated at the end of a process costing system. The costing of material components is more sensitive in a process costing system. Job-order costing is focused on each specific job while process costing focuses on departmental activity. Process costing uses only one work-in-progress account while job-order costing uses many work-in-progress accounts