It's not really a guitar thing... it is basicly a composition that your computer can "read" and play like sheet music.
Well that, im pretty sure that it's just using a midi format to send control signals sort of like "Pitch = Effect" Yeah, he's right, i can never remember that stupid Acronym
So is it something that I can download into it? That would already have the setting for the song without me have to set them?
a midi file contains triggers, and a midi device can read those triggers and perform commands based on them. For example, a midi soundcard has sampled sounds that it plays when it reads the triggers in a midi file. That's why a midi file can be so small, it doesn't contain the actual audio, only the triggers to make the audio. There can also be midi emulators that use synthesized sounds instead of samples.

For your midi footcontroller, it's sending the midi commands when you press one of it's buttons. A midi compatible device like an amp or fx unit with midi interface, can read those commands and change channels, settings, fx, etc... The midi controller itself contains nothing on it's own, all it's doing is sending midi commands. You set your amp/fx unit with what you want, then set it to store a midi command, and then press a button on your controller. After you store the command, everytime you press that button on the footcontroller, the amp or device sees the command and recalls all the settings you stored.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
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