Someone said up thread that only the British have classes. Such nonsense, most countries especially those who were colonised have strong social classes and groups.
And of course you can be a different race but still fit into the classes in Britain, as different races and colours have been a part of this country for hundreds of years in some cases, not just since the 1950s as some like to think.
Nigeria for instance has a large middle class and firmly separate upper class based in part on their old tribal system and on the British system. With lots of upper class and royalty but also lots of middle class. They also have a enormous working class as have a large population.
America has a class system but more defined by money, however the established upper class do not let the lower classes in even if they have education and money. In some ways there is less class mobility there and just wealth.
There are markers and identifiers in almost every culture, country and colour.
My family love education, one side is very posh and I refused to go to boarding school as the side of family, I grew up with and are closer to, went to good state schools.
Nearly all are highly educated either degree, masters, PhD and/or technical and professional qualifications. The ones who are not highly educated are mostly because their parent' married into a working class family so they have a slightly different outlook as they mix with different people with a different outlook. Ie a good job (not high status or well paid but steady and stable) but not necessarily one needing education is more their remit. These ones would identify as working class as they married into a working class family and their lives are more on that parallel.
Class is interesting as it is about social mobility and the lack of it in the UK. Yes you can go to uni and become a teacher, civil servants or doctor. But these opportunities are becoming less available for so many, due to a lesser education in the state system.
It just as hard for some children in 2019 to access a good education as it was in 1819. Also if no one you know, knows how to fill in a ucas form or even knows what one is, of course it is far harder to go to a Russell group uni or to oxbridge.
If getting an office job is rare in your area or in your family, as most people do retail, factory and manual work then it is an enormous task to go to uni and to become a professional of any type.
Not impossible just far harder to navigate. Then if you do, you may not get on the graduate training or right career path needed to get to the top as internships need money and many jobs still are about who you know. Lower and middle levels not so much but upper and top levels, absolutely.