citadel paints , what are the different types?

Ok so i just got back into painting games workshop minatures (hate the word models sounds to geeky lol) i was never any good at it as a kid but i know a few more tricks now thanks to the internet which i never had as a kid because it wasnt really around then lol , neither where mobile phones or mp3 players, (shocking) And finally to the question , The paints have changed a fair bit i, i use to have just paint and washes and now there's primer technical base foundation glaze dry and many more, i'm guessing some names are gonna be for the same thing but could someone tell me what each of them mean , please ps add any others you feel may be important scott