Here's how to break it down:
* 学 (gaku) means "study" or "learning"
* 生 (sei) means "life" or "being"
Put together, it literally translates to "learning life" or "life of learning".
You can use "gakusei" to refer to students of all ages, from elementary school to university.
Here are some examples of how you might use it in a sentence:
* 私は学生です。 (Watashi wa gakusei desu.) - I am a student.
* 彼は優秀な学生です。 (Kare wa yūshū na gakusei desu.) - He is an excellent student.
* 学生は図書館で勉強しています。 (Gakusei wa toshokan de benkyō shite imasu.) - The students are studying in the library.