Re: how does this work

If playing the games on the actual hardware isn't what you're after, first you'll download the system's emulator and install/unzip it to your computer. Then you'll need a rom of the game(s) you want to play. Next comes setting up your emulator which generally for older systems just means setting up your inputs and tweaking any visual and/or audio settings you need to. From there all you need do is just open the rom in the emulator and you should be ready to play.

Since you are asking about discs, I'm assuming you are asking about Gamecube or wii games being downloaded from here and played on an actual Wii console. Burning the games to a disc is generally not going to work. For Wii games, you can load them to a homebrewed Wii via USBloaderGX or Wiiflow, which are homebrew programs on your wii. For gamecube games, you can use nintendon't, which is another homebreww wii program that allows any wii to play gamecube disc image files on an SD card or USB drive (I would reccomend a USB Drive).

So before you play any games on actual hardware, make sure you have your wii set up with the homebrew channel.