Dual channel ram?

Well my friend told me to get dual channel ram cause its faster. It was the same price as normal ram so i got it. But now im wondering what dual channel does? how does it work?

It's kinda like putting your memory in a raid configuration. It uses two memory controllers for two sticks of memory. In theory it's supposed to to make 2x256 megs sticks faster then 1 512 meg stick. Think of it as raid for your ram sort of.