The serial console for Azure VMs is now generally available.
Until now (before preview of this feature) you will likely know the scenario when you have made changes to your VM that results in being unable to connect anymore and at this state you were forced to recreate your VM. With the serial console you can now virtually plu a keyboard in your VM and debug the misconfigured state or repair the network interface regardless if it is a Windows or a Linux VM.
More info here:
Windows VM serial console: https://docs.microsoft.com/en-us/azure/virtual-machines/troubleshooting/serial-console-windows
Linux VM serial console: https://docs.microsoft.com/en-us/azure/virtual-machines/troubleshooting/serial-console-linux