Signaling System 7 (SS7) is a set of telecommunication protocols used to facilitate the exchange of information between network elements in public switched telephone networks. It enables various functions such as call setup, routing, and billing, ensuring that calls are connected efficiently and accurately. SS7 operates by sending signaling messages over a separate channel from the voice data, allowing for faster communication and improved network management. This system is crucial for mobile networks and supports features like caller ID, text messaging, and roaming, enhancing the overall user experience in telecommunications.