Record direct – No microphone?

New computer – Windows 10
I haven’t used Audacity for a long time and have forgotten. I seem to remember (but not sure) that I can record direct from computer (file or internet) to audacity without using the microphone, so as not to pick up any background noise in the room e.g. a fan, my wife suddenly opening the door to tell me something etc.
Is this true and, if so can someone provided me with a link to a tutorial about how to do it?

This tutorial should be just what you need: