ok
u do the exam, and get a raw mark, then your exam mark and hte exam mark that corresponds with whatever rank you were in your internal assessments are averaged and this becomes your raw hsc mark.
the the BOS takes your raw HSC mark and judges into which band, (4,5,6 etc) hte mark you acheived would fall. if htey say anything about 80 is band 6 and you get 81, then you'd probably end up with an ALIGNED HSC MARK of around 91.
this has nothing to do with how many people got what mark, or anything like that, it just depends on what standard you acheived.
these marks are the ones that you see on your BOS Record of Acheivement, they are also ones used to get your name in hte newspaper, on teh distinguished acheivers list, all rounders and the such.
however to get your UAI, UAC take your Raw HSC marks and use a different Scaling process to determine your marks in each subject, and your total aggregate of marks (sum of 2units of english and best 8 units out of 500) to calculate your UAI..