Can anyone explain how AWS works? I did use my friend google but was overwhelmed with a flood of information about it. If I understand correctly, these codes give one access to a virtual computer (or cloud computing resources) but why are they so much in demand on this forum? And what is bitcoin's relationship to AWS?

Wikipedia says "subscribers have at their disposal a full-fledged virtual cluster of computers". So I'm just trying to understand how using them works. To access those virtual computers, one needs an own computer first. Why would one use a computer within a computer?

Sorry for all the questions guys, just hoping to understand what these AWS credit codes are meant for.