To understand what is an upper-level course, it is helpful to better grasp what does not constitute one. It is a safe assumption that a course whose number begins with a 1, like College Composition 112, is a freshman course. Sophomore courses generally begin with a 2, as in Calculus 220. Also, when a course begins "Introduction to," it is almost always a freshman course. It is useful to read the course description in your institution's college catalog, which usually makes clear what level the course is, along with any prerequisites to register for that course.
Senior-level courses are considered to be upper-level courses. These courses usually begin with a 4, for example Physical Anthropology 428. It is important to note that not every senior can register for a senior-level course. Some programs limit enrollment to students in programs offered by that department. You might be required to gain special permission from the instructor or from the department head to register for a course. You should have a good reason that you want to sign up for a course generally restricted to majors in that department.
Graduate-level courses encompass courses taken by graduate students studying for an MA, MFA, MBA or PH.D., the latter being a doctorate in a particular area, such as physics. Because the further you get in school the more focused your study will be within a specific discipline, graduate courses are usually taken in the area in which you are pursuing your degree or related areas.
Many students sign up for an independent study or directed reading in a particular subject area. Independent studies and directed readings are normally undertaken at the senior level of a four-year bachelor of arts or science program. You need to ask a professor in the area for which you want to take an independent study to oversee your work. You normally need to present a clear proposal on the topic about which you would like to conduct in-depth study. You will be required to update the professor overseeing your work on a regular basis and schedule meetings to discuss your process. Normally, at the start of an independent study, you sit down with the professor and set up specific parameters that must be met by the end of the semester.