A lesson or course; a group of students (a class); also a category or rank (e.g., classes in computing or product classes).
明日のクラスは3時から始まります。
Tomorrow's class starts at 3:00.
彼はクラスメートとよく話す。
He often talks with his classmates.
この製品は高性能クラスに分類される。
This product is classified in the high-performance class.