What is the differences between MODE_IN_CALL, MODE_IN_COMMUNICATION, MODE_CALL_SCREENING?

This is what the file says, but I can't fully understand.

/* modes for setMode/getMode/setRoute/getRoute */
    /**
     * Audio harware modes.
     */
    /**
     * Invalid audio mode.
     */
    public static final int MODE_INVALID            = AudioSystem.MODE_INVALID;
    /**
     * Current audio mode. Used to apply audio routing to current mode.
     */
    public static final int MODE_CURRENT            = AudioSystem.MODE_CURRENT;
    /**
     * Normal audio mode: not ringing and no call established.
     */
    public static final int MODE_NORMAL             = AudioSystem.MODE_NORMAL;
    /**
     * Ringing audio mode. An incoming is being signaled.
     */
    public static final int MODE_RINGTONE           = AudioSystem.MODE_RINGTONE;
    /**
     * In call audio mode. A telephony call is established.
     */
    public static final int MODE_IN_CALL            = AudioSystem.MODE_IN_CALL;
    /**
     * In communication audio mode. An audio/video chat or VoIP call is established.
     */
    public static final int MODE_IN_COMMUNICATION   = AudioSystem.MODE_IN_COMMUNICATION;
    /**
     * Call screening in progress. Call is connected and audio is accessible to call
     * screening applications but other audio use cases are still possible.
     */
    public static final int MODE_CALL_SCREENING     = AudioSystem.MODE_CALL_SCREENING;

Could you please explain them with examples?

At the moment, I use video chat service on WebView and I get MODE_CALL_SCREENING, it uses media volume, It should use 'calling' volume. How can I force it?

MODE_IN_CALL
You are talking to someone over audio only call (normal telephone call)

MODE_IN_COMMUNICATION
you are video & audio chatting with your friend or calling them on VoIP

MODE_CALL_SCREENING
your phone is ringing and you are checking then number before you answer the phone