Pop quiz, hotshot. What is the difference between this:
Time's up. The answer -- nothing. Same play. One is run out of the I formation, a classic dive option. The other is a more imaginative redesign of the option game, which is what you see Florida and others employ.
So what brought about the change in style? Look at the defense in the first two pictures. The main difference is the number of men in the box. Eight against the I, 6 in the shotgun. This is important for two reasons. One, it's one or two more guys to stop the dive part of the option or any other run you have in your playbook, and two, its easier to disguise pressure. If you want to blitz the strongside LB, he doesn't have to move until the ball is snapped. In the second picture, if he were to blitz from his position, it would have no effect since he has far too much ground to cover before getting to the QB or runner.
This is what fueled the change. By spreading out a defense, you make it state its intentions. Example:
The defense has to choose, do I hide the blitz and make it less effective, or do I go with it and risk something else opening up (In this case, the safety has taken himself out of the play by closing in on the ball, leaving the corner 2 on 1 on anything outside)? It wouldn't be a big deal on just running plays, but that is where the passing game comes in. The short, west coast inspired patterns hurt you horizontally.
In other words, the formations stretch you out, and the passing game fills the voids you leave when you bring heat. It's all about protecting the QB mentally and taking what the defense gives you. In this diagram, the safety has to tip his hand rather than stay on top of the slot, so he is easily picked up and the ball is easily thrown into the void. All of the misdirection and space hurts overaggressive defenses, and the short, controlled passing game hurts the conservative ones (tOSU, for one).
SEC teams have been able to contain the attack by playing bump coverage on the WRs and making Chris Leak keep the ball on option plays. And because skill talent hasn't been a UF strength of late, and because Chris Leak is a raging vagina with the football in his hands, it's worked fairly well. But as the talent increases, so too will the overall effectiveness of the offense.
In the meantime, Urban had to go to great lengths to get his athletes some space. One of the ways he did that, and one of the ways UF ran the ball this past season, was to throw a bunch of quick screens that doubled as run plays. It's just a toss, but the toss is overhand:
Now what you have is all three shallow defenders blocked, and a good athlete in space with the ball in his hands. At least that's the intent. This part of the offense was brought upon by the speed of SEC defenses shutting down everything they tried to do, which made Urban Meyer cry once (Amazingly, YouTube does not have the video of that). OU used this a lot during their championship run, it's just a way of getting 4 yards without the cloud of dust. We do versions of it, too:
This is hardly a complete guide, but I hope it helped shed light on the building blocks of the offense.