What is the yellow dot on my iphone?

The yellow dot on your iPhone is most likely related to the privacy feature introduced in iOS 14. Whenever an app is using your microphone or camera, a yellow dot will appear at the top right of your screen to indicate that these sensors are currently being accessed. This feature was introduced to provide users with more transparency and control over their privacy. You can view which app is using your microphone or camera by swiping down the Control Center from the top right corner of the screen. If you see the yellow dot while you are not using any app that requires the microphone or camera, it could be a sign of potential privacy breach and you should investigate further.