Advancement to the next grade or class (e.g., promotion to the next school year or rank).
成績が良ければ進級できる。
If your grades are good, you can advance to the next grade.
進級試験を受ける学生が多い。
Many students take the promotion (advancement) exam.
彼は留年して進級できなかった。
He failed to advance because he repeated a year.