what is this exactly? Is it like an extra week of holidays in the middle of the semester which coincides with school holidays? and do other universities also have it?
Yes its a week off, with no (or limited classes) during that week. It usually coincides with school holidays where possible. Most other unis have a similar week as well, and it depends on the uni whether its in the same week or not.
A question.... if my course has no exams in first year, does that mean my holidays start when everyone else has stuvac and exams? Or will I just have normal lectures then?
Haha yeah that's going to be a drag. My HSC was like that, I finished halfway through, and had nobody to talk to because they were all thinking Chem and Economics...