This is the 689th most frequent Japanese word.
授業
"授業" means "class" or "lesson."
In this sentence, "授業" refers to a specific academic session or class that occurred today.
今日の授業はとても面白かったです。
Today's class was very interesting.
Here, "授業" specifies the upcoming academic session or scheduled lesson.
次の授業までに宿題を完了してください。
Please complete your homework by the next class.
In this case, "授業" is used to indicate the general existence of lessons or classes within the school context.