
The bootdisk feature is what enables the camera to load Magic Lantern at boot time.

Magic Lantern enables the bootdisk flag in your camera and then installs to the SD card. This flag tells the camera if it should try to load and execute software stored in the SD card. My understanding is that the only change that is done to your camera is to enable the "bootdisk" flag, which is a very minor change.

I think something not everybody understands is the Magic Lantern does not install into your camera but to the SD card. The chances of bricking your camera are extremely low (but not zero).
