This is the 78th most frequent Korean word.
일부
"일부" means "a part" or "a portion."
The word '일부' is used here to mean 'a part' or 'a section' of a larger whole, indicating that not the entire book was read.
이 책의 일부는 제가 읽었습니다.
I read a part of this book.
In this sentence, '일부' means 'some,' referring to a subgroup within the larger group of students.
일부 학생들은 수업에 참석하지 않았습니다.
Some students did not attend the class.
Here, '일부' again means 'some,' used to specify a portion of the group of people.