General

The UK has a large and highly productive higher education sector with over 2 million students enrolled at undergraduate and postgraduate levels. Around 450,000 of these students are postgraduates, with about 86,000 enrolled in research degrees and another 210,000 or so enrolled in coursework degrees. International students make up a major part of the total UK student population, around 13% but Australian students contribute only a small amount to this number. So if you get there you will stand out!

In terms of variety and choice the UK has a great deal to offer, there are 96,000 full time academic staff working in a total of 116 universities and 53 Colleges of Higher Education. The institutions themselves vary greatly in size and level of specialisation as well as being dispersed between the great metropolis of London, major regional cities such as Birmingham and smaller university towns.
The UK system places a high priority on research, but like Australia, for the most part has academics engaged in both teaching and research. Over £3.7 billion from all sources is invested in research in the UK each year. By comparison Australia invests

While there are some differences between the administration system of higher education in Scotland, Wales and Northern Ireland compared to England for most postgraduates the differences are unlikely to be important since they mainly relate to undergraduate intake and local student funding. Far more important for your research should be differences between, and opportunities offered, at different tertiary institutions.

The College system within some Universities - Colleges as Universities

One aspect of British higher education that Australians may at first find confusing is the system, mainly at the older universities, of having colleges within the university that function as worlds to themselves. These colleges are frequently known by their name followed by the University they are part of, for example Kings College, Oxford. They have their own identity and profile and sometimes even exist in geographic regions quite separate from the University proper. For example Royal Hollaway, University of London. The colleges may share much of the infrastructure of the university of which they are a part but have a high degree of autonomy. Frequently it will be the College rather than the University to which you apply for entry.

Colleges as Housing
Just to add to the confusion many of the newer universities in particular have colleges in the sense of some Australian universities. These colleges are colleges of accommodation, though they may offer some tutoring work to their postgraduate residents. However while this quirk might seem to have the potential to mislead once you a researching on the web the differences should be quite obvious now that you are aware of dual uses of the word.