What is a POS?

A retail point of sale system typically includes a cash register (which in recent times comprises a computer, monitor, cash drawer, receipt printer, customer display and a barcode scanner) and the majority of retail POS systems also include a debit/credit card reader. source: https://www.google.com.ph/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwiv6Z_rzfbWAhVBso8KHW3cCm0QFghDMAM&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FPoint_of_sale&usg=AOvVaw0GEPbjNpaRrCXZ43eT2CJL