well a lot of motherboards come with cheap onboard sound, with chips mostly made by realtek or idt these days. sound quality is usually far superior with a good soundcard. creative used to make the best ones. you can hear a huge difference between a creative and cheap onboard sound, especially in anything using midi files. with soundcards, or onboard chips, there are preprogrammed sampled voices that are used for playback of many different types of sounds. add-in sound cards usually have way better preprogrammed sampled voices. if you play a midi file you can tell diff in like 2 seconds. if you don't have really good hearing and only listen to cds/mp3s it might not be as important a factor to you. if you have an idea what you might wanna buy search it on newegg.com and check out the reviews. it will at least keep you from getting something really crappy. newegg.com is prolly the best online store in the usa to buy computer/networking stuff.