A school subject or area of study (e.g., math, language, science) within the curriculum.
小学校では算数や国語などの教科を学ぶ。
In elementary school you study subjects like math and Japanese.
その大学では専門教科を中心に履修する。
At that university, you mainly take specialized subjects.
教科ごとに成績をつける。
Grades are given for each subject.