What are the differences between art schools and universities?

Universities tend to train people who want to talk about or manage art, to be cultural mediators (theorists, art critics, directors/administrators of cultural venues, troupes, etc.).

The schools tend to train people who want to make art (all the ‘creative types’, artists, designers, decorators, stylists, etc.).

Public universities and art schools award Licences, Masters and Doctorates.

Public schools award ‘titles’ or ‘certificates’ that the CNCP (Commission Nationale de Certification Professionnelle) classifies into 5 levels. See:
https://www.campusart.org/home/catalogue-campusart/les-etudes-diplomes-dart/?lang=en