How to record audio on Audacity either from a microphone or to capture the sounds of another program

To record on Audacity, you simply need to set up your microphone, add a track, and press the "Record" button ...

If you can get past the terrible logo, Audacity 4 looks pretty great

Over 25 years Audacity has gone from simple audio editor, to a UX nightmare. If you can get past the terrible logo, version 4 ...