Point-of-Sale Electronics - A POS terminal manages the selling process by a salesperson accessible interface. The same system allows the creation and printing of the receipt.
If you have a retail or really any kind of business then you must know about POS. There are several communication protocols POS systems use to control peripherals.
Among them are
EPSON
Esc/POS
UTC Standard
UTC Enhanced
AEDEX
ICD 2002
Ultimate CD
5220
DSP-800
ADM
787/788
A Retail POS system typically includes a computer, monitor, cash drawer, receipt printer, customer display, and a barcode scanner. The majority of retail POS systems also include a merchant account system card reader.
Here is a good video on selecting a good cash drawer system:
