noun
new student; entering student; admitted student
Refers to a person who has been admitted to or is entering a school, often used in the context of new enrollees at the start of an academic year.
今年の入学者は去年より多い。
There are more new students this year than last year.
入学者にはオリエンテーションが行われる。
An orientation is held for entering students.
入学 is the noun for 'entering a school' or 'admission', whereas 入学者 refers to the person who enters.
Compound of 入学 (entering a school) + 者 (person).