For those not familiar to this sort of thing, think of the Debug log like your own private 'in program notepad'. Use this to write messages to yourself during program execution. For example, you could write the graphic modes that the user has on his system, or just little alerts to let you know your code execution made it to a certain point in the execution without interrupting it. I'm sure you'll find a lot of uses for this! See the example if you're still lost.