Is going to college abroad recommended for someone right out high school? Can you give me some differences/similarities and pros/cons?
Read threads already on here and Google first.
NYU has a program where you can go abroad your Freshman year-full year in London
Two broad a question: I know many students who went straight to the UK and are having/had a wonderful experience, many for whom it would not have been a good plan, and a few who tried it and came home either at winter break or after the first year. Irl, everybody going away to college or university- whether in their home state, across the country or across the world- does a lot of adapting in the first few months. Some people find that harder than others.
It doesn’t really matter, though, if it’s a good idea for anybody but the person asking the question.
Academically, the US & UK systems are very different. In the UK your grades are based less on continuing assessment (daily homework, quizzes, etc) and much more on fewer, bigger exams (at the extreme end, your entire grade for a class can be based on the final exam). As @Conformist1688 noted on your other thread, you apply straight into your major, and that is all you study, so the system is great for people who already know what they want to study. Typically you have few (if any) class choices in the first year, and even when you do have choices (incl in later years) you choose from a short list of related classes, so it is really important to read the fine print of what each course is at each university: International Relations or Politics or whatever subject is not the same at university A and university B.
The student life experience is also very different. Most unis are not residential in the same way as most in the US: fewer dorms (although there are always some, esp for international students), and more students live ‘out’ (in their own accommodation) from the beginning. There are only a few significant exceptions: Oxford, Cambridge and Durham, which are ‘collegiate’ universities, in which you belong to a college within the the university- but even there you typically ‘live out’ during your 2nd or 3rd year. St Andrews in Scotland has most first year students in uni housing. Most of the school ‘activities’ are student run and managed: you won’t have the big school-run team sports (there are team sports, but nothing like, say, the Big 10).
In general, there is an expectation that you will manage your university experience yourself, as an adult. There are resources, but you have to find them (there is a new student / new international student orientation process, and there are ‘welfare’ officers, which relates to general student wellbeing, not money!). Students tend to look to each other more than to admin.
Finally, if you have never spent time out of the US, you need to be prepared to hear different things about the US and it’s government than you may be used to. UK Students tend to be more informed in broad terms about US current events than US students are about the UK, and they will have strong opinions. Even people who are fans of America and Americans in general will have some sharp comments to make, and of course your responses have to reflect your status as a guest in the country.
^ Warwick also has guaranteed campus housing for first years.
@collegemom3717, I thought that was typical for top-tier UK unis? Granted, Edinburgh and Glasgow would be heavily commuter and the London schools (as well as the Red Brick Unis in large cities) would have a large commuter contingent as well (and none of the London schools would have something resembling an American collegiate campus with all of them having residences scattered throughout London, some in hotels, etc., and some having even the academic buildings scattered throughout various parts of London).
…and those are the ones that most US students will be applying to, @PurpleTitan! 
It is evolving. Most have housing at least first year for internationals, and there are some that can accommodate most first years, but it is still most common for students to organize their own housing. In cities where there are several universities, there is also dorm variant in which enrolled students at any of the local universities can get accommodation, so you can have students from other unis in your building. Unite Students is one of the providers, and they have grown exponentially over the last number of years, into a significant provider of college accommodation (24 cities now).
Mainly I was trying to make the point that most unis are less campus-centric than in the US and that for many/most students (depending on the uni), their housing in less likely to be run by the university for some or all of your time there.
I think it’s a great opportunity, but if you’re not confident (rather than certain - everything is going to be an exploration, after all) it’s what you want either take a gap year (bonus - you can make some money to ease your burden before going) or go to a UK uni that offers years abroad. Some of it depends what you’re studying, too - don’t do medicine anywhere you don’t plan on living long-term as you will need to re-do your residency, and if you aim to study languages don’t worry about it as you will travel with your degree.
Hope that helps!
I applied to UK unis and received a few offers, but in the end I decided it was better for me to stay in the US for my undergrad.
The reason being simply that although I truly loved the subject I applied for (Int’l relations/poli sci), I still wanted the chance to explore other subjects I might not know about. Thus, if you are completely certain about what you want to study at university and there is no way you could imagine changing your mind, I think it’s a great way to be efficient in regards to both time and money, and focus entirely on what you want to (instead of wasting time with GE’s, etc)
Going to the UK right out of high school certainly is possible if you have the qualifications necessary for your intended course of study, and if you feel ready to make that leap.