Common examples of hooks are:
Under Represented Minorities (URM)
Recruited athletes
Legacies
Development cases: children of people who are likely to become generous donors
First generation
Children of celebrities and politicians
Children of faculty
Note that, except in the case of recruited athletes, all of the above hooks are BY NATURE, i.e., by simple fate of being born to a certain family.
Then, there are hooks that are, on the other hand, BY NURTURE:
Olympic medalist
International violin virtuoso with Carnegie Hall appearances
Intel ISEF winner
UN speaker
Chess grandmaster
Patented inventor
etc. etc.
Note, also, that such hooks play a greater role in college admissions at highly selective schools. At single-digit selectivity rate at these schools with so many excellent applicants than they know what to do with, these hooks can make a significant difference.
Also note that not all hooks are of equal value. Each college has its own priorities and these priorities can even change from year to year in its attempt to build a particular class.
“Also, I’m very passionate about programming/CS. My life is CS. Most of my academic competitions, my classes, my ECs, and my job literally orbit computer science. Would that be considered a hook?”
In short, yes, as long as you can stand out from a crowd of applicants with a similar “passion.” If you don’t stand out, and CS and programming is ALL you’re about (“My life is CS”), there’s a danger then of being labeled “one-dimensional,” i.e., not well-rounded. Whatever your passion, it’s far better to be either “pointy” (stand out from the crowd) or well-rounded.
Lastly, I’d note that, other than the obvious examples of hooks listed above, there are many instances of well-rounded applicants being admitted to these highly selective schools. So, even if your parents can’t afford to donate $10M to a school of your top choice, non-athletic, not a concertizing virtuoso, haven’t published a NYT best selling book, etc., don’t be discouraged. Don’t look around at what others do, either. Just follow your own path with deepest interest and the results will take care by themselves.