Intelligence is the equivalent of knowing all the words in the dictionary, all the rules of grammar, sentence structure and so on.

Vision is the equivalent of imagining up a good story.

You can know even the most esoteric of words and all the rules including the most obscure ones but all that knowledge means squat if you can’t come up with a good story. That’s why billionaire company founders are typically visionaries, not those who can belt out the best lines of code or those who can build out the best spec’d hardware.

To put in another way, intelligence is “force” and vision is “direction”. Columbus found America because he knew where to look for land (direction i.e., vision), not because he had the best sailing vessel (force i.e., intelligence). 

People often confuse both. There are many cases where someone who’s not very intelligent has vision because they intuitively know where to go and what to do. Most self-taught people could fall under this category; they know what to do, but often do not possess the knowledge and skills to do it and hence set out to acquire just enough of both to do what they want to do.