The Wii U is a different console to the Wii. The Wii U however is compatible with Wii games and accessories.
No, the Nintendo Wii cannot play Wii U games
No. Gamecube game were compatible with the Wii but they're no longer compatible with the Wii U. Wii games are however still compatible with the Wii U.
No, the Wii cannot play Wii U games. It's actually the opposite - the Wii U can play Wii games.
The Wii U can play all Wii games since it is backwards compatible.
Yes the Wii U is backwards compatible
No, the Wii U cannot play Nintendo DS games
Yes, the Wii U is backwards compatible with Wii games. You need to insert a Wii disk, then go into Wii Mode by selecting the option from the Wii U menu. You'll need a Wii controller to use Wii Mode.
The Wii U is compatible with Wii games. There is no difference in the disk sizes. (Be aware that the Wii U does not support Gamecube games.)
Yes, the Wii U is backwards compatible with Wii titles. (It cannot, however, read/play Gamecube games.)
Yes as the Wii U is backwards compatible with all Wii Games, Downloads and Peripherals, but not GameCube ones
As long as the game is from the same region as the Wii system, it will be compatible.
You can use any Wii games or Wii U games and software. Wii U games don't work on Wii, however, and the Wii games require the TV screen.