An EPOS system is what a shop, cafe or trade counter uses at the point of sale. It scans or selects items, takes payment, prints or emails the receipt and records the sale. Behind the scenes it also reduces the stock count and adds to the day's takings.
The real value comes when the till is connected to the rest of the business. Stock levels can trigger reordering, takings can flow into the accounts without retyping, and head office can see how each site is trading. For a retailer with several branches, that shared view replaces a good deal of end-of-day paperwork.