The feature was introduced as smartphone privacy became a growing concern. Users increasingly wanted to know when applications were accessing microphones and cameras. Rather than allowing this activity to happen invisibly, Android provides a clear visual warning so users can recognize sensor activity immediately.
When the green dot appears unexpectedly, you can check which application triggered it. Swipe down from the top of the screen to open the notification or quick-settings panel and tap the privacy indicator. Android should show whether the camera or microphone is being used and identify the responsible application.
