POS stands for Point of Sale; POS technology is used mainly at retail locations such as stores, supermarkets, restaurant, etc. When a customer would like to purchase an item or pay a bill a POS system is extremely useful to register the purchase, keep track of inventory, purchase details such as time, date and store location and input all this data into a database which then can be used for data mining purposes.

POS systems have changed the face of retail. Now, a small or large business can easily keep track of what products customers buy. A business can keep data of all purchases and compare this data from a year earlier or other stores that they own within or outside of a region.

POS systems usually work via infrared bar code readers, a register and bar code reader are hooked into a computer terminal. For instance, when you go to a supermarket, you place your items on a conveyer belt, the register assistant then scans your item with the use of the infrared bar code reader. At this time, you see the price of the item and it is added to the total of all items purchased, however on the backend of the system, lots of data including all the information about the product (the price, size, brand name, etc) and the time and date of the purchase is recorded onto the computer for later analysis.

With POS systems everybody wins. The consumer wins because the check out is fast, reliable and accurate. The retailers win because they are able to keep track of sales easily, inventory and have tons of data available for further analysis.

POS systems continue to become more powerful. Many supermarkets now keep track of their customers by starting customer rewards program. Most supermarket customers join the rewards programs and they receive a small key fob with a barcode to distinguish them in the computer. Now supermarkets are not only able to keep track of which items are purchased, but who purchased them. The same can be said about store credit cards. When a store has your personal information, they can easily keep track of certain customers and the purchases they make. These innovations have made marketing to customers extremely focused and profitable.

Bar Codes are part of the POS process. A bar code is a bunch of vertical lines that an infrared reader can read and interpret as data. The bar code includes a UPC number which stands for Universal Product Code. Most items that are sold in a retail environment have their own UPC so they can be purchased and tracked efficiently by the POS and computer system.

Besides bar code readers, a UPC can also be input directly into the cash register or computer. Sometimes if a bar code is unreadable, the assistant will manually input the code using a keypad.