student vs enrollee

student and enrollee both are nouns.

Word	Noun	Adjective	Verb	Adverb
student	Yes	No	No	No
enrollee	Yes	No	No	No

As nouns, enrollee is a hypernym of student; that is, enrollee is a word with a broader meaning than student:

student: a learner who is enrolled in an educational institution
enrollee: a person who enrolls in (or is enrolled in) a class or course of study

student (noun)	enrollee (noun)
a learner who is enrolled in an educational institution	a person who enrolls in (or is enrolled in) a class or course of study
someone (especially a child) who learns (as from a teacher) or takes up knowledge or beliefs