What's the Equivalent of US 'A Levels'?

It's a bit puzzling, so I thought I would ask. What's the US equivalent of 'A Levels'? As I understand, A Levels are pretty significant in the UK educational system, so how does it compare to the US?

In the US, the closest equivalent to 'A Levels' would be Advanced Placement (AP) courses and exams. The AP program, overseen by the College Board, offers college-level curricula and examinations to high school students across a range of subject areas. Students who perform well on AP exams can often receive college credit, similar to how high-performing A Level students can begin university with advanced standing.

However, it's essential to note some differences between the two education systems. While the UK educational system narrows the scope of focus to three or four A Level subjects in the last two years of high school, the US system encourages students to continue studying various subjects throughout their high school years. In the US, a typical high school student takes multiple AP classes across different disciplines, along with regular high school classes.

Another significant difference is the grading system. A Level qualifications are graded from A to E. In contrast, AP exams are scored on a 1-5 scale, with5 being the highest score.While the A Levels and APs are conducted quite differently, they share similarities in being college-level courses that provide opportunities for students to earn post-secondary credits early.