A point-of-sale (POS) is the location where customers of a small business exchange money for the products or services sold by the small business. A POS transaction occurs when a customer buys or returns a product or service and occurs either at a brick-and-mortar store, on a mobile app, or in online checkout.

A POS system may be a simple cash register, a single computer, or an integrated computer network with point-of-sale software. It may also be a mobile device like a laptop, tablet, phone, or specialized terminal that can be used remotely for online sales transactions. POS terminals may be either stationary units tied to a computer inside a brick-and-mortar business, a mobile unit like an iPad, or a unit for online transactions.