One of the big differences between US education and European education is that there is no exam that must be taken or passed to receive the high school diploma. If you complete the required number of courses with a passing grade or better, you get the diploma. In other words, there is no US equivalent to the German Arbitur or the French Bac. (The ACT and SAT are required by some universities, but count for only part of the entrance requirements. There is also no “passing” or “failing” grade on those exams. Schools may draw a line at a specific score, but getting a very high grade will not guarantee admission to a university, and students with low scores can be admitted on the basis of other factors.)
All high schools are essentially the same, too, although there may be minor regional differences based on the kind of students the school is likely to receive. We don’t have “technical high schools” for example (although there may be a few scattered around) versus “academic high schools.” Instead, most schools teach a variety of programs, and students are encouraged to take courses based on what they want to do when they graduate. (That said, our school district does have a variety of high schools with different programs, and students are encouraged to apply to schools with programs that they are most interested in. However, all of them do have both academic and technical tracks.)
For example, when I started high school, we lived in a small city that had one high school for all students in the city. There were several different programs within the high school, and students were encourage to choose a program of study based on their plans for after high school. There was an academic track for those who intended to go to university (and which included more foreign languages and sciences, based on the state university’s entrance requirements), but there were also technical tracks like mechanics.
My family moved to a much more rural area after my second year of high school. The new school had a very small academic program (about 20 students in my year), but it was very strong in agriculture programs and secretarial programs, for kids who planned to stay on the farm, or who wanted to be prepared for a secretarial position if they couldn’t find a husband. (That was definitely the attitude of those students at that time.)
For teens who choose not to attend school, or for adults who never finished, there is the GED option, which allows you to take a series of exams that proves you know the basics of English, math and science, as taught in high school. While it is technically the equivalent of a high school diploma, it does not include the more academic subjects, so students with GEDs are often accepted into university on a provisional basis, if they are accepted at all. High-ranking private schools often will not accept students with only a GED at all (but they won’t accept students with poor grades, either). State universities and technical colleges, however, will often accept a GED in lieu of a diploma. (With the up-and-coming use of online education, though, some school districts are now offering full-fledged diplomas for curriculum completed as independent study or online courses.)
In the US, though, there isn’t a lot of emphasis on career-oriented training until much later than in Europe. Generally, students are well into high school before they actually start to take classes geared toward specific careers, and students in academic tracks generally don’t start until they are actually in a university.
However, after graduating from high school, there is a much wider range of kinds of schools, including technical schools that train students for specific careers (often two-year associate degrees), and universities that offer the Bachelor’s degree with a greater inclusion of liberal arts/humanities/“it’s good for you” kinds of classes.
The Master’s degree is generally expected to be in a field that is related to the Bachelor’s degree. If you change fields completely, you may be expected to take additional courses at the Bachelor’s level before you will be admitted into the Master’s program of your choice. For example, I have a Bachelor’s in French, and a Master’s in French Linguistics, but actually looked into getting another Master’s in Audiology. However, there were several background courses that I was expected to take before they would even consider accepting me into the Audiology program. Since none of the courses were offered locally, I was not able to get into that program.