NTSC & PAL
What is NTSC?
NTSC is an encoding system used in North America (NTSC-U) (excluding Greenland), parts of South America, Japan (NTSC-J), and other regions in the world.
If you bought a Wii new in North America, it will be NTSC-U.
What is PAL?
PAL is the European standard encoding system and is used in many places throughout the world.