men's jewelry wholesale What does POS machine mean and how to operate. Please explain it in words that are easy to understand. Someone knows how DCC dynamic currency conversion, how did it work

kleitz 601 market street wholesale jewelry wilmington de 1920 Pre -authorization is that you go to the store, first swipe the card to pay 1,000 money, make a deposit, and live for a day. The other party calculates that you spend a total of 500, okay, 500 to the hotel account, and 500 will be returned to you. If it was not pre -authorized, then 1000 that was brushed into the hotel account at the beginning. When you are going to check out, the hotel can only withdraw 500 cash,