This is the second element of earned value management. Actual Cost is the total cost incurred for the actual work completed to date; or simply put, it is the amount of money you have spent to date.
As per the PMBOK Guide “Actual Cost (AC) is the total cost actually incurred in accomplishing work performed for an activity or WBS component.”
Actual Cost is also known as Actual Cost of Work Performed (ACWP).