The traditional divide in Oxford was between town and gown. That is now cut across by other social divisions, however, and there's a third component to Oxford's population, in the form of tourists. (At this time of year, central Oxford is completely polyglot, with as almost as much Italian, French, Spanish and German to be heard as English.)
There is a divide within Oxford university between the arts and humanities dons and the scientists. The former seem more closely tied to their colleges and may spend most of their working day in their rooms there, while science staff spend most of their time in their laboratories. There's also a population of "post doctoral research assistants" - like Camilla - who lack college affiliations.
References to "the university" usually mean Oxford University, but Oxford has a second university, Oxford Brookes, which has just as many students (more undergraduates, fewer postgraduates). I was surprised to learn that Brookes students are actually wealthier on average, and from more privileged backgrounds, than OU students.
There are also a lot of people outside the universities doing research or research-related work: in biotech, software development, hospitals, and so forth. In many ways these people have much more in common with university staff than with (say) people working in retail.
No doubt there were always divides between wealthy guild members and peasants or workers, but the "town" side of things is also more diverse now. There's a huge distance, social and geographical, between residents of North Oxford who commute to London to work in the City and unemployed manual workers in Blackbird Leys.
Many people from Europe, children and adults, come to Oxford to do language courses over the summer. They're more like tourists than students in many ways; they don't have much in common with the university undergraduates, anyway.
In general the undergraduate students leave Oxford over the summer - they are turfed out of their college rooms so their colleges can rent them out for conferences etc - when the tourists are at their peak.
Some random rules for typing people
- if they're wearing academic robes or dress then they're university staff or students
- language is not a reliable guide, given how cosmopolitan Oxford is: anyone speaking Polish or Punjabi is most probably a local, and Oxford gets a lot of domestic tourists. (My fairly blandly Australian English is a lot less distinctive than anyone speaking Geordie or even a strong local Berkshire dialect.)
- anyone actually looking at the buildings is probably a tourist.
- anyone wearing extremely high heels is probably a local: if they are under 20 and their shoes cost less than £20 they're girls in from the 'burbs, if they are over 50 and their shoes cost over £200 they're North Oxford housewives.
- if they're ardently defending (or attacking) Chomsky's contributions to linguistics, chances are they have some connection with Oxford university.
- if they're in a group of thirty and just got off a tour bus, or are following a guide with a flag around, then they're tourists.
- cyclists are probably not tourists, unless they're on hire-bikes.
- most of the people carrying cameras are tourists (but not all, one resident photographer can be found at Oxford Daily Photo).
And what am I? A local under any formal definition, since I have no affiliation with the university and am (despite being domiciled in Australia for tax purposes) a resident of Oxford. But I can sometimes be seen wandering around with a camera and I do look at the buildings. And I play with a gamelan group attached to the university; and most of the people I know work for the university. Some people might even call me an academic tourist...