Go to Help in Payroll to read about this.  Payroll - Help - Help Topics - Index tab - Generate Accrual Entries and Generating Accrual Entries.  It explains it pretty well.

Kim,

Runing this task with take the existing payroll in the new.prt file and create cost enteries. It will create a debit to cost and a credit to accural. This is just for the raw labor so you can get current Job Cost reports before the Payroll checks are run.  When you do print and post the checks the process will debit the accural account for the raw labor.  Hope this helps!