Help with MCU ports

Hello, when I use the Arduino IDE am I supposed to use the same com port for different boards?

The OS of my personal computer or the MCU device?

I have another separate question since you seem knowledgeable. I recently bought the NodeMCu with esp8266 and I am pretty sure that I have successfully installed the ch340g driver for the USB to serial converter. By going to device manager on my pc and seeing the ch340g name under ports doesn't that mean that mean that I have successfully installed the driver??