Wii Remote

Wii Remote
The wii remote is the controller that works with the nintendo wii. At first there was some speculation about how it functioned, and many still are unsure about it. The controller is motion sensitive. If the player was playing a baseball game, they would swing the controller like a bat. If they were fighting with a sword in-game, they would slash like a sword in real life, and so on.

Numchuck
The numchuck slots into the bottom of the wii remote with a wire. It's only features are 2 buttons, "c" and "z", and a control stick. Like the main controller it is motion sensitive.

Use in Metroid Games
In Metroid Prime 3 Corruption, the control stick on the Numchuck is used to move Samus, and the wii remote is used to aim and shoot.