Cash Register and Indicator
A cash register or till is a mechanical or electronic device for calculating and recording sales transactions, and an attached cash drawer for storing cash. The cash register also usually prints a receipt for the customer. In most cases the drawer can be opened only after a sale, except when using a special key, which only senior employees and the owner have. This reduces the risk of employees stealing from the shop owner by not recording a sale and pocketing the money when a customer does not need a receipt but has to be given change. In fact, cash registers were first invented for the purpose of eliminating employee theft.