many years ago students of all ages used to be in the same classroom. there used to be only one teacher for the entire school. nowadays there are different classroom for student or different ages and grades.
in the past,teachers used to talk, and the students used to listen. or sometimes the students just repeated the teacher's words. nowadays it's common to see students working together in groups around tables and discussing things aloud.
many years ago, school allowed teachers to punish students, and even hit them. some teachers used to beat students with a cane or a wooden paddle.
nowadays detention is one of the most common punishments in some countries. students go to a certain area in the school during break or after classes and do academic work. sometimes teacher have them write the same thing over and over.
parents were more involved in school in the past. teachers knew their students' families better. so when there were learning problems or bad behavior, teachers used to go to the students' homes to discuss the problems with parents. nowadays the school counselor talks to the student or the parents.