Just Intonation vs. Equal Tuning

Ok, I am just weighing in on the mathematics/logic of the scale/tuning. I read up on the "Just intonation" and I thought it made sense until I read down partway through #2 and realized we were not talking about the scale I was thinking we were talking about (now I know the one I am thinking about is the Equal Tuning scale). I think I need to discuss these concepts more in class if I am going to understand them...