These settings are used to define each payroll department. Then, each employee would be added to one of the departments. If a department is not set for an employee, then they default to department 1.
This is where the GL accounts are selected so that the employee department posts to the correct GL accounts.
Deductions
Setup each deduction with a GL account and give it a name that will appear in the employee record and on timecards.
Benefits
Give each benefit a name. The benefit will be further defined when editing the employee record.