* 100-level courses are introductory courses that cover the basic concepts and principles of a subject. These courses are typically required for all students, regardless of their major.
* 200-level courses are intermediate courses that build on the knowledge gained in 100-level courses. These courses typically cover more advanced concepts and principles, and they may require students to have a certain GPA or to have completed certain 100-level courses.
* 300-level courses are advanced courses that cover specialized topics in a particular subject. These courses typically require students to have a strong foundation in the subject area, and they may require students to have completed certain 200-level courses.
* 400-level courses are capstone courses that allow students to apply the knowledge and skills they have gained in their coursework to a real-world problem or project. These courses typically require students to have a strong foundation in the subject area, and they may require students to have completed certain 300-level courses.
In addition to the level of difficulty, college courses may also be numbered according to the department that offers the course. For example, a course that is offered by the English department may be numbered ENGL 101, while a course that is offered by the math department may be numbered MATH 101.
The numbering of college courses can vary from institution to institution. However, the general system described above is followed by most colleges and universities.