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