I don't know if this is the right forum for this (as it also deals with piano), so... please correct me if it isn't.

I found that the Middle C on my keyboard is an octave higher than my Guitar's Middle C. I'm kind of confused... is it supposed to be this way? Because I definitely remember once making the mistake of tuning my low E string to the next E octave by accident, and as a result, the string broke.

And while I haven't really made any progress (or actually have planned yet) in learning how to play piano/keyboard, but... I don't really think I'm able to change the tuning of it.

So can anyone clear my confusion please? :P
The guitar is somewhat of a transposing instrument, yes. It sounds an octave lower than the piano.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.