If you are familiar with retail outlets you will notice that they have POS system at the counter (well, at least most of the retail establishments have be it the one with touch screen or the standard Point of Sale system).
When I was in my final year in University, a friend proposed an IT project for a bunch of us to set up POS systems at his father’s chain of mini markets and that was the first time I got to know about all this POS set up.
There are actually many brand and type in the market. For example, one of them is IBM point of sale systems. A standard POS system usually has a display mount, POS keyboard, receipt printer and terminal.
Or if you are looking for one without keyboard, you can have the one with touch glass. And if you are planning to accept credit card and use barcode on your product, make sure you find point of sale system with magnetic stripe reader and barcode scanner.
They are many companies that sell POS system which even maintain and do all the upgrade job for you. Make sure you find one that has good reputation because in the business especially for retailers, efficiency in working devices will perk up your numbers of satisfied and returning customers.