What is the difference between professor, Tutor and mentor?

[gihel]

I tried the 3 options but I see nothing

Thank you so much

[max]

Well, they have different permissions on the menu items. Out of the box it's already configured with some differences, but working with the menus you can actually change everything and make them have much bigger differences.
So: they are already different and you can make them be as different as you like. Provided you need 3 different roles, which might as well not be the case.