Electives are your 'free choice' courses that allow you to select courses of interest and give you flexibility within your program. There can be limitations on the number of electives, both general and within the discipline area, so please check the requirements of your specific program to see how much 'room' you have for electives.
You can add structure to your electives by adding core courses from another Major area within your degree. Choosing another major or a minor can be a good way to help you select general elective courses; some degrees even have double majors available.
There is no single 'list' of electives across the University. For more information about elective course options review your program structure or have a chat to staff at Student HQ.