Choosing a degree
There are lots of ways to study computer science (CS) at the ANU. This page aims to list the common undergraduate degrees and give unofficial advice on the benefits and drawbacks of each choice.
The main ways these degrees differ is how open ended or rigid they are and whether they have a mandatory honours year (an extra year with a research project).
Remember that your first choice isn't final: 50% of ANU undergraduate students will transfer from their first degree!
Degrees
Bachelor of Computing (formerly Bachelor of Information Technology)
The BComp (formerly BIT) is a 3 year, relatively open ended computing degree without any required research/honours components. It's more vocational than theoretical and is a great way to quickly launch yourself into a software development career.
Bachelor of Advanced Computing (Honours)
The BAC is a 4 year, somewhat more rigid computing degree with an honours year. It's like a BIT but with more compulsory courses and slightly more of an academic focus.
Bachelor of Advanced Computing (Research & Development) (Honours)
The BAC R&D is the BAC, but with lots of research project courses throughout the degree and high ATAR and GPA requirements. It's aimed at high academic achievers who want to be exposed to academic research and it's a good pathway into postgraduate study. Some such students find this degree too restrictive; the Bachelor of Philosophy gives greater flexibility if the option is available.
The next two entries are not computing degrees per se, but you can use them to study mostly (or even, for the PhB, exclusively) computing.
Bachelor of Science and Bachelor of Science (Advanced) (Honours)
The BSc is the ANU's standard 3-year science degree, which can be used to study any of the physical or natural sciences, as well as things like mathematics, and (most relevant here) computing. Compared to any of the above degrees, it is vastly more flexible; however, it does require the completion of a major and a minor (or two majors), so you will have to spend at least a little time studying something other than computing. (This is not a bad idea anyway!) A minor is only four courses, so this isn't a huge ask; maths is a popular choice, but you can study any science that takes your fancy (and even some subjects outside the Colleges of Science, like economics, are available as BSc majors or minors).
This is especially recommended to anyone who's interested in exploring the sciences or mathematics, or wants maximum flexibility with no grade requirements, as long as you don't mind piecing together a minor from somewhere.
The BSc (Advanced) is simply a BSc with an integrated honours year and tougher grade requirements.
Bachelor of Philosophy (Science) (Honours)
The PhB is the single most flexible STEM degree at ANU, allowing you to study any science courses (this includes all COMP courses), with no need for majors or specialisations; just a minimum number of research or "advanced" courses. It is very specifically targeted at high-achieving students who intend to pursue postgraduate research, and even provides a small amount of leeway with course prerequisites & similar.
The drawback? This is a very selective degree, with both high entry requirements (a very high ATAR or equivalent, plus an application process) and harsh grade requirements (High Distinction average) to continue in the degree. (If you fail these, you'll drop into a BSc or BSc (Advanced), as described in the last section, which isn't too bad.)
This is similar in some respects to the BAC R&D, but infinitely more open-ended. You should do the PhB if you want to do the BAC R&D but are limited by its inflexibility: perhaps you want to study lots of maths or physics alongside CS, perhaps you don't want to fully commit to CS but want to study it anyway, or perhaps you want to skip a few introductory courses as you have lots of prior knowledge. It's an excellent pathway into postgraduate study.
It is very difficult to transfer into the PhB after second year.
Bachelor of Engineering (Honours) in Software Engineering
After a brief hiatus, the software engineering curriculum has been reworked, improved, and the new software engineering degree is a special variant of the normal Bachelor of Engineering. This is another honours (4 year) degree, similar in some ways to the BAC, but featuring a number of "systems engineering" courses shared with other engineering disciplines, plus some software-engineering-specific later-year courses. It is even less flexible than the BAC, but is also accredited with Engineers Australia, an accreditation that, unlike the ACS accreditation of some other computing degrees, can actually be meaningful for purposes other than visa applications.
Bachelor of Applied Data Analytics (Honours)
The BADA is another fairly rigid 4 year degree with a large emphasis on computer science and statistics.
That was overwhelming; which do I choose?
If you want the most flexible degree possible, and you meet its strict requirements, take the PhB. If you don't meet those rather extreme requirements, or don't want to put yourself through the stress of continuous grade requirements, pick the BComp if you'd really just like to study computing, or the BSc if you want more flexibility and are willing to spend at least a little time studying further afield.
If you're happy with a more structured 4-year computing degree, pick the BAC (R&D) if you meet its relatively strict requirements and want the chance to pursue multiple research projects, the BAC for a slightly lower-stress, very mainstream, respected 4-year computing degree (you can still do some research if you want to!), or the BComp / BSc (as described in the previous paragraph) if you don't care about either of those things. (You can still apply for, and complete, an honours year after doing any of the 3-year degrees.)
If you specifically want to pursue lots of research, definitely pick the PhB if you can. If not, you have a choice: BAC (R&D) (if you meet its requirements) for easy ways to more research projects, or BSc for most flexibility and lowest stress (but you'll have to spend a little more effort pursuing research opportunities at your own initiative).
The BEng in SE and BADA are specialist degrees; look them up if they sound interesting to you. They're both fine degrees, if a little heavy on required courses.