A class in education has a variety of related meanings.
It can refer to a course itself: a class in Shakespearean drama.
It can be the group of students at the same level in an institution: the freshman class; or the group of students which graduates from the institution at the same time: the class of 2005 (cf. alumnus/a).
It can also refer the a classroom, the building or venue where such a lesson is conducted.
In some countries' educational systems (such as Taiwan's), it can refer to a subdivision of the students in an academic department, consisting of a cohort of students of the same academic level. For example, a department's sophomores may be divided into three classes.
In countries such as the republic of Ireland the word can mean a grade: 1st class is ages 4 and 5, 2nd class is ages 6 and 7, 3rd class is ages 8 and 9, 4th class is ages 9 and 10, 5th class is ages 10 and 11, 6th class is ages 11 and 12.