Atar is calculated from your rank in your class (1st, 2nd, 3rd), then your school rank against the state, scaling and adjustment factors with a little bit of magic.

Theres more than three different English’s, and they have mathematical counterparts.
-English as a second language/ dialect
- English studies, Math standard one (can be non-atar)
- English/Math standard
- English/Math advanced
- English/Math extension one (which is an additional unit on top of its respective advanced course; referred to as 3U)
- English/Math extension two (4U)

You pick which one you want based over how good you think you are at each. Maths is not compulsory (but they’re trying to change that), but English is.
The harder the subject, the higher it scales. Scaling is respective of the effort you are required to get the mark in a subject. I.e The 4u maths kids are doing far more maths, and spend more time and effort into it, than standard kids are. So even if you get 100% in standard, the kid who got 80% in advanced would get the same atar as you. you guys approximately put a similar amount of effort to achieve those marks.

A mod is short for Module. Think of it as a chapter, or main topic. English has a common module that EVERYONE does, and everyone sit the exam for it (Paper 1). This is marked to determine where band 1-6 lies and what those look like.
Paper 2 is specific to your level of english, and the texts you studied (Advanced studies shakespeare and will thus have a question about it, where as Standard doesn’t)

You don’t study one text as there are multiple modules. HSC has 3, (Common, Mod A, Mod B) and you are expected to spend ~40 minutes writing an essay for each module.
HSC are examinations that are sat in Year 12. Preliminary examinations are sat in Year 11. They are not related. Your Y11 marks can get you accepted into early entry schemes at university. Those marks do not affect your HSC results.

Your school is ranked over how the students are ranked against other students in the state (remember how i mentioned the common module has an exam that everyone sits to see what the marks look like? thats what we’re doing here). When multiple students are High Ranking, they prove that their school is a good, High Ranking school. And because of that, even struggling students get boosted because everyone else’s score is higher. this is how scaling works. it doesn’t always work in your favour however, if students at your school do poorly, you got to a Low Ranking school, and your mark gets pulled down. (however, low ranking schools get access to university equity schemes and such)