The top one is the sim card slot and the bottom one is sam1 and sam2.
Expanded Information: 2. SAM Card: The Secure Access Module (SAM) is the core of security control in smart card applications. pos machine: POS (Pointofsales) in Chinese means "point of sale", the full name of the point of sale information management system, is equipped with a bar code or OCR code technology terminal reader, cash or barter amount of cashier function. Its main task is to provide data services and management functions for commodity and media transactions, and non-cash settlement. References: