If you want help with something show some effort. In your case better explain why you need to know and what you have come up with so far. If you have done some good work, expect to get some good help. If you haven;'t done any work, go do some work and then ask again.
I want to know the general modules for chash register to design our system which is checkout system used in mini supermarket. By knowing these it will help me to define its componenets. For example I suggested Security module and Bar-code proccessing.
I work for a small point-of-sale company. Modules can include Inventory, Employee Management, Security, Payment, Vendor Management, Accounts Payable, Accounts Receivable, General Ledger, Label Printing, eCommerce Integration.
Those are just to name a few. Do you need any other details?