The green dot on your iPhone indicates that an app is using your iPhones camera or camera and microphone together. This is a security feature introduced in iOS 14 by Apple to show you when an app is using your camera or microphone. Common apps that will display the green dot on your iPhone include FaceTime, Instagram, Snapchat, or the camera app itself. If you want to turn off the green dot, you cant do it directly because it is a built-in security feature and cannot be turned off.