If one software calls it extract, and another calls it convert .. who cares?

You quickly learn what it does and go from there.
The technical side of it is kind of mundane. Yes the audio is a separate part of the 'file bundle' at a certain level, but some users don't really need to know/understand that

'Extracting' the audio part and 'converting' it to a new format could make both terms correct.
Just my thoughts
/it likely runs thru a convertor of some sort along the way, even though you are extracting just the audio

Make your sound your own!
.. I do not work here, but the benefits are still awesome