English question, please help?

Dictionary.com says: 'a branch of instruction or learning: the disciplines of history and economics'.
The Free Dictionary says: 'a branch of knowledge or teaching'.
Your Dictionary says: 'a branch of knowledge or learning'.

I, in this case, would define it as different subjects.

With a range of programs and courses available, the University has experienced increased demand across many subjects.

Major, Subject.

Areas of study or a "branch of knowledge" as definr.com defines it.

To put it simply-subjects. You will understand this word better when you study.