Point of sale (POS)
A point of sale (POS) system is the software, and sometimes hardware, a business uses to take orders, record payments and keep sales records.
In a café or restaurant, the POS is the centre of service. Staff enter orders, the POS sends them to the kitchen, adds tax and service charge to the bill, and records how each bill was paid. At the end of the day it shows what sold and how much came in.
A restaurant POS differs from a retail one. It has to handle tables, rounds of orders added over a meal, split bills and kitchen routing, not just items scanned at a till.
Older systems ran on a dedicated terminal with a cash drawer and a receipt printer wired to it. Cloud POS systems run in a browser or an app on phones, tablets and PCs, keep data online, and let owners check sales from anywhere. They depend on an internet connection, so a backup such as a mobile hotspot is worth having.
Example
A café in Bhaktapur runs its POS on a phone at the counter. The cashier takes an order and records a cash or QR payment, and the order appears on the kitchen tablet. At closing, the owner checks the day's sales report from home.
KalasOS specifics
KalasOS is a browser-based POS: the waiter, cashier, kitchen and kiosk screens share one live order stream. Payments are recorded as cash, your venue's static QR, or a split of both; KalasOS records them but does not process them. There is no card terminal, cash drawer or ESC/POS printing; bills print as PDFs from the browser. Every screen needs an internet connection.