How do I understand the concept of overapplied and underapplied? How do I journalize it and close out the the difference between cost of goods sold and factory overhead?

I don't understand what it meant to have debit or credit balance on factory overhead.

CHapter 15 Job Order Costing and Analysis 20 Factory Overhead Balance Is Overhead Costs Overhead Is Journal Entry Required Underapplied Cost of Goods Sold Actual >Applied Debit Actual Applied Overapplied Factory Overhead # Credit Cost of Goods Sold.. .. Underapplied or Overapplied Overhead . To illustrate, assume that Road Warriors applied $200,000 of overhead to jobs during This equals the amount of overhead that management estimated in advance for the y further assume that Road Warriors incurred a total of $200,480 of actual overhe during 2015. Thus, at the end of the year, the Factory Overhead account has a debiv halance reflects manufacturing costs not assigned to jobs. This s Inventory, Finished Goods Inventory, and Cos