What is dreamcast boot disc?

The Dreamcast boot disc is a tool used to play backup games on a Sega Dreamcast console. It allows the user to bypass the console's copy protection and play copied games or games from other regions. The disc is typically burned onto a CD-R and inserted into the Dreamcast along with the copied game. The boot disc is considered a controversial tool as it is illegal to make and distribute copies of copyrighted games. However, some Dreamcast enthusiasts use the boot disc as a way to preserve and play rare games that are no longer available for purchase.