Disney Infinity is a awesome video game for PS3, Wii U and Wii. It uses the same tech that created Skylanders. That's right. You need to get figurines (sold separately, I think), and put them on a device that makes the figurine's character appear in the game.
But here is the best part. You can do whatever you want in the video game. Even build entire worlds from the ground up!!! But none of the playable characters are original. They are based off of some of the video game/movie characters that Disney created. Captain Jack Sparrow from Pirates of the Caribbean, Mr. Incredible from The Incredibles and Sullivan from Monsters Inc. come with the game.
Unlike Skylanders, which the device is the Portal of Power (designed to look like it is made of stone and has a magical theme), the device for Disney Infinity is the Infinity Base (with a smooth, futuristic theme). The Infinity Base has two slots for the playable characters and a third slot for a Play Set. Play Sets are levels that also have figurines.
Anyway, The difference between Play Sets and the Toy Box is that in Play Sets you must use a character from that Play Set and must play by the Play Set's rules. Toy Box allows all characters to be used no matter their origin and you do whatever you want in the Toy Box.
Here is a picture. NOTE: Image is from Wikipedia.
This is the starter pack.