Why does My Mobile Phone Screne light up When Im Talking On It?

Your mobile phone screen lights up during a call primarily to facilitate easy access to call controls and features. The proximity sensor detects when the phone is held close to your ear, turning off the screen to prevent accidental touches. When you move the phone away from your ear, the screen lights up again, allowing you to see the call interface or other notifications. This design enhances user experience by preventing unintended actions while on a call.