HM-10 Bluetooth AT command from Arduino Uno

At any time while the sketch (program) is running i can type in AT and hit send on the serial monitor and it writes to the HM-10 module and not get passed on to the connected device
the AT command will disconnect the Bluetooth device connected to the HM-10 module
I am at a loss on how the HM-10 modular can tell that's its from the serial monitor and not
BTserial.print("AT");
The BTserial.print("AT"); just gets passed on to the attached Bluetooth device (phone)