The Payroll menu item is where you run your Payroll Export to your pre-configured payroll software.

You can pre-configure your Payroll Export details under System Settings > Payroll Settings.

The options that show under the Payroll menu depend on the payroll software export that has been configured.  Most will have filter options to filter by Employee, Department and Pay-period.  Your data will then either export to a file to import to your payroll, or if using PaySync by Aussie Time Sheets your data will push straight into your payroll software via API.  With most Payroll Exports, you have the ability to preview onscreen the data that will export out and then click to export.