必修 (hisshū) means “required subject”

More examples

この学科では、二年次の必修が五科目あります。ko no gak ka de wa ni nen ji no his shū ga go ka moku a ri ma su

In this department, there are five required courses in the second year.

Refers to a subject made necessary by an educational program for all students in its scope.

必須科目hissukamoku: A subject required for students to complete a particular educational program.

学校や課程の定めによって、履修が義務付けられている科目。gak kō ya ka tei no sada me ni yo tte ri shū ga gi mu tsu ke ra re te i ru ka moku

必修 (hisshū) is a Sino-Japanese compound of 必 (hitsu, "certainly") and 修 (shū, "study"), meaning study that cannot be omitted.

A Japanese course may contain both 必修 (hisshū) subjects and elective subjects, so the label shows which classes are compulsory.