In my android studio, the phone are not being recognised, only loading is coming, Dies anyone know about it?

  android, android-studio

I have been trying to connect my phone through usb and android studio is not identifying it. Earlier I have run programs on my mobile but suddenly it started to show only loading. I have tried to clrar cache in srttings but ehn I try to find ADB in devicr manager, I could not find it. I dont know what to do and I am really struck, help me out please

Source: Android Studio Questions