Unfortunately :-) I just got a degree from Oxford, partly to learn the difference and, in a nutshell, the UK has 3 years of college/university and you study only one subject, your "major". In the US, it is 4 years and the first couple of years you study everything and the kitchen sink before you get to years where you mostly have courses in your major.
The UK grading system is based on 70 points (basically) where the US is 100 points. It's a complicated difference in grading that almost did me in:
https://www.soas.ac.uk/studyabroad/c.../file77182.pdf
Getting a "59" on my first paper, which would have been failing in the US, it took me 4+ papers before I could wrap my head around not getting in the 90's all the time.
The tutoring system is unique too. I was online but had just gotten a degree before from an US university online and where the US will have a "class" of 30-50 students with a professor interacting and assigning topics for discussion, etc. the UK online system divided those students up into 4 tutoring groups who had limited discussion with the whole -- we really only got to chat with the other 6-7 people, whoever showed up to the weekly chat in our tutor group. Too, the discussion exercises were just for our tutor group and not really required and even when people gave answers to the questions, they were more-or-less directed at the tutor, not each other so there was little discussion back and forth!
The papers we had to write for the UK were a "choice" too, so more individual than most of the time with the US papers (both degrees were in history so it's an honest/straight forward comparison). But what got me with the papers is the teaching style was wholly different, with the UK you give them back what they have taught you whereas with the US they want more original thinking, your own thesis, etc. I had already been trained to come up with my own point of view and defend it in the US and it was hard for me to adapt to the UK with its "What were the major changes in whatever over this period. . ."/"The major changes were (1), (2), (3), and (4) with these examples." You couldn't think of your own changes or ways of describing changes, it was almost, but not quite, parroting back but since the reading material (very free-form -- huge choice of "suggested" reading, no textbook(s) like in the US) was not directly related to the questions you had to write your paper on, it got interesting as to whether you could tell them what they wanted to know, the way they wanted to be told
I had trouble with that since I had 60+ years of doing it the US way and wasn't in the habit of knowing by default what they wanted so only got mid-50's to md-60's scores.
The thing that really blew my mind though was my UK history course required using Excel and Access databases and you already had to know or be capable of learning (have enough computer background) how to use them in detail, as themselves. So, it was a computer, statistics, and history course all in one which was hard for me to wrap my head around as we don't use computers in our history courses (fortunately I had two degrees, one in history and one in sociology and the sociology had a course in "research methods" which is what they were basically making you learn in the UK history course).
With history there was a lot of differences as the UK is only the size of Minnesota and we have 50 Minnesotas/little countries and how the US developed over time is different from how the UK has been over the last 2000 years, LOL so I'm lucky I even got an upper lower second
It was fun in the tutor chat each week too, I missed half of what was said/typed as I didn't have the slang/language! LOL. The chit-chat part was often over my head.