I need some information on which universities in sydney are the best for STEM courses?

Ok I know when i ask about universities the answers are going to be bias, but frankly I have no idea about the reputations of them etc. so yeah...

Anyway, on r/cscareerquestions everyone says 'do computer science as a university course'. But I'm assuming that is coming from american people so its different from australia.

I was looking in some university information booklets today and they mostly had information technology courses and only a couple had computer science. Now i thought IT was mainly not coding but some of the 'careers' that could lead from IT courses said stuff like software developing etc.

And also i thought computer science was harder but the atar requirement for university of sydney is only 76 whilst the UNSW course has an atar requirement of 91. And at sydney uni information technology is an atar of 88. which is higher then their computer science class. But whats the difference?? like between the IT and CS courses but also between different unis courses that have vastly different atar requirements???

I'm confused and i need someone with some relevant knowledge to weigh in on this please