What are A levels?

Google can't help people who insist that Africa is a country, or that there's a single language called "European".

Jokes aside, A-Levels is a pre-university 2-year system after high school that is compulsory in UK (& potentially some other former British colonies; but very much optional in my ex–british colony country that shares more similarities with America than UK, educationally). UK degrees are usually just 3 years instead of 4 precisely because A-levels cover freshman year content. I hear there is no concept of major & minor in UK.
You specialize in 3–5 subjects, and your grades can play a role in determining target school admission (so yh, Bristol Uni engineering, Oxford/Cambridge, medical school, hyper competitive Russell Group economics departments, etc., are off the table for giveadvicepls); so you pick A-level subjects that have at least vague similarities with your tentative intended future degree faculty.