There are thousands of colleges and universities in the United States. Nearly half of the high school graduates in America go on to college. Most go to large state universities. Some of these universities have 40,000 or more students. There are also many small universities with only a few hundred students. Large universities have many buildings, each building for a particular subject. Students often must go from one class in one building to the next class in another building across campus. They may have only a few minutes between classes to go from one building to another. When students begin the university, they must take classes in many subjects. These are the required courses. English and math are usually required courses, and often a history and a science course are required too. Students will study mostly required courses during their first year. Later, they will specialize, and take courses in one subject.