What is a department?
A department is a group of faculty members with expertise in a specific academic field (or discipline) who offer courses (and usually degrees) in that field.
For example, an English Department has scholars in English literature and, often, rhetoric and composition; it may also include linguistics scholars who focus on English.
An English Department then offers degrees in English: this includes areas like creative writing and English literature at the undergraduate level; at the graduate level, often additional specialization is offered, such as literary theory, composition studies and focused literary study.
Sometimes two or more departments with similar academic content may be organized into an academic division. In other cases, a division may include multiple colleges or schools.
Basically, the word “division” is used by some universities to create another layer in addition to departments, within colleges, within the university — the “division” layer can come between departments and colleges, or between colleges and the university. And in some cases, you may find other uses for the term “division.”