What is the purpose of ATC transponder codes during IFR flights?

Transponder codes are essential for enhancing aircraft visibility to air traffic controllers during IFR (Instrument Flight Rules) flights. When an aircraft is equipped with a transponder, it automatically sends out information about the aircraft’s identity, altitude, and location to air traffic control radar systems. This allows controllers to track the aircraft's movements in real-time, helping to ensure safe separation between aircraft in busy airspace. The unique transponder codes assigned to each flight enable air traffic controllers to distinguish between different aircraft and provide them with necessary instructions, thereby improving overall safety and efficiency in the airspace system. This functionality is crucial for maintaining situational awareness for both pilots and air traffic controllers.