The admissions rates for American universities are useless because the system (no cap on number of applications) encourages students to apply to more colleges, which feeds a cycle where students see lower admissions numbers and apply to more colleges to raise their chances. Because lower admissions rates look better in league tables, colleges have no incentive to curb the practice. There's some use in comparing institutions, but as an absolute, the percentage means little. There are colleges encouraging hopeless candidates to apply to improve their numbers.
In the UK UCAS only allows 5 and you have to choose between Oxford and Cambridge. Meanwhile every year the US media finds someone who got into all 8 Ivies.
@californiaisdreaming I posted some of the differences. In my opinion, having been to a UK university for undergraduate, a US one for postgraduate, and a child who is a student at an American college.
US:
Flexibility, multidisciplinary studies, very wide variety of types of institution.
4 years, and usually more expensive (certainly so for international students). Students have a major, a core curriculum that can vary from "nothing required" to quite detailed, and then options/electives that you can use to either deepen your main subject or explore more. Most professional degrees are postgraduate. In many cases no specific major is required (for example medical school) as long as the required prerequisite classes are taken.
Top universities have generous aid, which includes living expenses.
Smaller schools in particular tend to be more parental and the social life is more school-organised. For example at private universities you're often expected to live in halls all 4 years and meals are typically catered, though self-catering can exist for the juniors and seniors.
UK (England and Wales): Student applies directly to subject(s), more in-depth in that subject, shorter course, great for specialists. Student life is more independent, even in halls.
Cheaper (usually), with better payback terms on loans, though the student loan does not fully cover living expenses.