[@Kho] So, in my university, I have to complete a number of courses to complete my degree and graduate. Each of these courses typically lasts one semester and focuses on one subject area (with some variation). While many of the courses are hard requirements (core courses), the rest are electives from which you can choose if they are being run that semester.

While I thought I would be graduating by the end of the month, I miscounted the number of electives I had yet to complete and I am stuck with one remaining. Normally, this close to graduating, you can find a workaround. I have no such luck, so I'm stuck for another semester.

Now, you normally take more than one course per semester. Studying full time usually has you undertaking three or four courses at once. Part time study is usually one or two courses. Some people with too much time and mental stability/illness [i]overload[/i] their courses and take five or more per semester.

What BBeast means by underloading is the opposite. I will only be taking one course, so I will be doing less than usual.

That's the general idea. It can be different between Australian tertiary education establishments.