To record the screen on an iPhone, first, add the Screen Recording control to the Control Center if it's not already there. You can do this by opening Settings, tapping Control Center, and then adding Screen Recording from the More Controls list. After that, swipe down from the top right corner of the screen to open Control Center, tap the Screen Recording button (a circle within a circle), and wait for the three-second countdown to start recording. To record audio along with the screen, press and hold the Screen Recording button in Control Center and tap the Microphone button before starting. To stop recording, tap the red status bar or the Screen Recording button again. The recording is saved automatically to the Photos app.