A POS (Point of Sale) machine, also known as a point-of-sale terminal, is a core device that connects the payment link in commercial transactions. It supports payment collection via multiple methods such as card swiping, QR code scanning, and NFC (Near Field Communication) induction, and is widely used in various offline consumption scenarios including supermarkets, catering outlets, retail stores, and convenience stores.

Its core functions include three aspects: 1. Reading payment information such as bank card details and mobile payment account data; 2. Connecting with payment systems to complete fund settlement; 3. Printing transaction vouchers (receipts). Additionally, some high-end models also support auxiliary functions like inventory management and sales data statistics, helping merchants simplify the checkout process and improve operational efficiency.

In terms of types, common POS machines are mainly divided into three categories: desktop POS machines (fixed at checkout counters and connected to computers and printers), mobile POS machines (connected to the internet via 4G/Wi-Fi, suitable for mobile payment scenarios such as food delivery and street vending), and smart POS machines (equipped with touch screens and capable of installing apps to expand functions like member management). These types can meet the operational needs of different merchants