Dean x rector x provost x chancellor: Qual a diferença

Dean, Rector, Provost and Chancellor. I translated it to portuguese and they were all the same, 'reitor' but what's the difference?
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Hi there Renata,

"Dean" is a person who is responsible for the discipline of students in a college or university, especially in the city of Oxford or Cambridge.

"Rector" is the head of certain universities, colleges or schools of Britain.

"Provost" is a senior member of the staff who organize the affairs of some universities, that can be used in any place.

"Chancellor" is an honorary title of an official head of a university in Britain.

As you can see, there are many words but with the same meanings, the only difference is the local.

I hope I've helped!

Source: Oxford Advanced Learner's Advanced