What does the seoson pass do in black ops 2?

It gives you all the DLC packs as they come out. Throughout the next year there will be 4 DLC packs with new maps, weapons, camos, etc. They usually cost 15 bucks each therefore 60 dollars total for the 4. The season pass just gives you all of them for 10 bucks cheaper. Only problem is you won't know what they are until they come out.