1A lesson or course, or the group of students who take it together (a class); also used for a grade or category of things, such as a 'class' of cars.
今日のクラスはリスニングの練習が中心だった。
Today's class was mainly focused on listening practice.
彼女とは同じクラスで、いつも隣の席に座っている。
She's in the same class as me, and she always sits next to me.
このホテルはビジネスクラスの部屋が人気だ。
This hotel's business-class rooms are popular.
英会話のクラスに週に一度通っている。
I attend an English conversation class once a week.