Hos does the 4-year college works?

The simple answer is that you can either pick a major which is very specific like Nursing or Accounting or Mechanical Engineering and apply to a college that ensures they teach the requisite courses and skills to graduate and get a job doing those things or you can go to college without a declared major, dabble and make a decision after a year or two, on what you might like to major in.

If you know you already want to be an Architect or become of Vet (animal doctor), then you should apply to those schools that specialize in that. However, if you are uncertain, then applying to a liberal arts colleges makes more sense. LACs, are designed like Elite Private Boarding Schools where you live on a beautiful college campus in dorms and eat in dining halls and attend classes in mostly historical buildings with very small class sizes in a Socratic Learning style or sometimes even smaller on a one on one Tutorial style. You take various courses like STEM classes, Languages, Humanities, English and the goal is get a well rounded liberal arts education. Most LACs, still want you to pick a major. Most people at LACs pick some humanities major although these days you can even study CS and Engineering at some of them. Many students who go to LACs end up applying Grad School. The thought being that after 4 years of getting a well-rounded educational, you have a better idea of what you might what to specialize in like Journalism, Education, Medicine, Business etc.

I think most 1st generation or low income students apply to larger State research universities because of cost but more importantly, they have high expectations of getting a good job with their college degree. Wealthier kids from better zip codes whose parent may have multiple degrees and have prestigious professions often don't rush into a profession choice right after high school. They end up at Ivy League schools and LACS studying all sorts of things before they decide to apply to Law, Business, or Medical school.

Hope this is helpful to you. Good luck.