POS (Point of Sale) is a multifunctional terminal. It can be installed in designated merchants and credit card acceptance locations, connected to a computer, and automatically transfer electronic funds through the network. It has functions such as support for consumption, use of pre-authorization, balance inquiry, fund transfer, etc., which is safe, fast, and reliable. The POS system was first applied to the retail industry, and then gradually extended to other service industries, such as finance and hotels. The use of POS systems has also expanded from enterprises to the entire supply chain.