Difference between DK and DK Gold?

Hi there. I'm looking into getting into Dungeon Keeper and already saw that gig.com is often recommended to get the game, along with KeeperFX for some Bugfixes and whatnot. Now, if I check gig.com, all I see is Dungeon Keeper 2 (not interested in that right now) and Dungeon Keeper Gold. So, my question is, what is the difference between the "regular" Dungeon Keeper and Dungeon Keeper Gold (and is there anything else I should know to get started)?