Exactly how does CD ripping work?

Does anyone know of any article that explains the technical details of how CD ripping works in a PC?

For example, I just recently learned that an integrated sound card will degrade the ripped audio. And of course will also degrade the playback being the card is in use during playback. But I don't see how this affects CD ripping, like say for iPod playback.
Be careful opening that link at work. There were some funky ads on the page.
Strange - when I open the link I only get 3 very small ads. One is for blank CDs, one for a cassette to CD copy program, and one for a Usenet trial. I didn't see anything that I'd remotely describe as "funky."