What's the difference (between school and college)?

Not a lot, it seems to me.  To most kids, school is something your parents  have wanted you to get through.  (Some of these parents have struggled to get work, because they hadn't been to school, or dropped out; they're convinced of the usefulness of school.  Other parents are both busy working, and just need a place to stash you until they return from work.)  The attitudes of kids towards school depends heavily on their parent's attitude, even if the kids and the parents fight about everything else.)

College, in contrast, is, on the face of it, a place a kid wants to be: away from the parents, lots of potential for---well, let's call it 'Romance', and improved chances of getting a job.

In my own case, I loved college.  Many of the things I was taught were the same old things from high school, but they were more logically linked together.  You knew why they were joined together, they made good sense.  Often, your college courses went no further than high school courses; in fact some of my high school courses were even a tiny bit more advanced!  But in some cases, you knew your college courses were giving you the real deal, something you would not have known if not for your college education.

Unfortunately, in some junior colleges, you just get a second chance to get some material you ought to have picked up in school, but then you were young, and distracted, and stupid, and have sports practice.  Now you're older, smarter, got even more things to do, but it's a second chance, and you don't waste those.

So, most kids who've been to college, really know more, and are capable of more things, than high school graduates.  But it depends on the person.  It's quite possible for a kid who's been through college to be just as dumb and unmotivated as a high school kid, unfortunately.  That's why god made HR people, who must know what they're doing.   But unfortunately there's no way to ensure that your new college graduate employee is any good.