It's exactly like that. When we're done with high school (5 years of it), we're around 17. Then, for those who wish, they can enter college. College prepares you for university, the big league. College last 2 years for those who want to go to university, and for those who want to get a job after college, well, it's 3 years (programs like basic nursing, basic computer sciences, etc).
So, for those taking the 2 years-route, they have a choice. You can enter natural sciences, which is divided in pure sciences and health sciences (pre-med). In my college, both programs were about the same in size (250-250). It's basically the same thing, except pure sciences has 1 extra math class, and health sciences has 1 extra chemistry class. So out of these 500 people, about 300 were actually targetting medicine. Only ~ 25 entered med school at the end of these 2 years... We can enter medicine right after college, if your grades are good enough, and for those who weren't so lucky, well they can go to university, in a program like biology, biochemistry, etc, and then reapply to enter it.
Now for those interested in other university programs (arts, literature, geography, etc), they enter a college program like Human sciences, etc.