What is the difference between "In approval Process" and "In Approval process 50%"?

In approval process % means how many approvers approved the reports, so if you see 50% means that that 1/2 approval levels approved timesheet or expense report  if you have 2 levels to approval one level approved and one remaining to approve. If you see in In approval process with no % it means the manager open the report and then canceled without approving the report of timesheet.    So In Approval Process is the same as In Approval Process 0%.