[ThisWillDestroyYou]

I don't know if where you are choosing to attend is similar to here in the States, but this is how it works here.

Typically it depends on your major. There are general classes that you must take like English Composition 1 & 2, History 1 & 2, College Algebra, etc., basically "core" curriculum. However, depending on your major, you are required to take classes designed for that major. They tend to allow you some flexibility, but not much.

For example, if I want to major in a science field, say, Computer Science. I will have to take College Algebra, Trigonometry, Pre-Calculus, Calculus I, Calculus II, Calculus III, and Discrete Mathematics. Those classes are mandatory. However, they will allow me some flexibility with my science courses, but I still have to meet a required allotment of credits in those courses.

In other words, if I major in Computer Science, I have to take two separate sequential courses in different science fields. So, say I'm interested in Physics and Chemistry. Well, for a computer science major I am required to have a total of 16 credits in science, but they have to be from 2 separate fields and sequential. So, to meet those requirements I can take Engineering Physics I and Engineering Physics II, along with Chemistry I and Chemistry II. Or say Biology interests me, I could take 2 biology courses, but I'd still need two different science courses from biology, but in the same field.

Now, say you're interested in an English Major, or something of the sort. Typically you'll have to take English Composition I and II before you can take any literature courses. So, in this case, those composition courses are pre-requisites, which may be the case for a class like comparative literature.

To sum up:
1. You have core courses EVERY one has to take.
2. You have pre-requisite courses for your desired major, and sometimes for specific classes.
3. When you meet those pre-requisites you're allotted some flexibility in the courses you take, but it has to meet the Universities diversity requirements for your major (in other words you might be able to take comparative literature as an elective, but it might not meet a requirement for your major so it could potentially be a waste of time).

The best idea is to sit down with a counselor at your prospect school, or shoot them an e-mail. They'll be able to give you a more direct answer.