What is wii connect 24?

Answer 1

It's a Part of the Wii that always stays on unless it has no power or is in RED mode. It basically just receives feed from the internet like Wiimails, Mariokart tournaments, update checks, shop channel updates, etc.

Answer 2

Wii connect 24 is a service that makes your wii look for updates and other internet information such as news channel updates or messages sent by friends. To activate this option, you must enter on wi menu, then wii settings and WiiConnect24 (you have to setup your internet connection first). You may also turn it off on the same option.

You will notice that your WiiConnect24 is working because the wii LED changes to yellow when is turned off, you can turn off temporally your wiiconnect24 by pressing and hold the power button until it turns red. Wii connect24 will activate again when you turn on your wii.

When this option is active, the wii heats because is still working but the internal cooling system is not, and the life of your wii may reduce, so I suggest you to turn it off, anyway, when you're playing, the wii automatically looks for updates, so it is not really necessary.