A POS system or point-of-sale system is a set of devices, software and payment services merchants use to make sales in person. A POS system manages customer purchases, accepts payments and provides receipts. A point of sale is also where a merchant and customer conduct a retail transaction. It is where the merchant calculates the sale price for the customer, creates a record of the transaction and provides payment options. Many merchants use POS systems to perform these actions. Modern POS systems also generate reports, help manage inventory and track employee hours, among other things. A POS system calculates a customer's purchase amount, adds sales tax, processes the payment and logs the time and date of the transaction. After completing the transaction, many POS systems generate a paper and/or digital receipt as well as adjust inventory records. POS systems are the modern version of old-fashioned cash registers. Typically, the three main components of a POS system are hardware, software and payment processing services.