What is the Difference between "De" and "Du" in French?

I heard "Du" is something like De+le , but im not sure if this is true. Can someone explain this to me?
Thanks.

Well it's true. See, a french person won't say "Je mange de le chocolat" but "Je mange DU chocolat" ("I eat chocolate"). So du = de + le :)

Anyway good luck with french ;)