Maybe dumbest question ever

Hi everyone, looking to get into pc gaming, and am going to build, here's the question, i never see sound cards mentioned in build recomendations, where does the sound come from.

All motherboards have on board audio, if you want a dedicated sound card for some better audio quality you plug the card into one of the PCI-e slots on the motherboard and then plug your speakers or headphones into the new card.

After installing the new card and its drivers the computer will use the new card to output the audio, you may have to mess with your windows setting to make sure the new card is the default audio device.

oh ok, thank you