The main difference between middle school and junior high is the age of the students. Junior high is for older children, and the range of the ages goes from 7th grade to 9th grade. Junior high school can be intimidating for students, as there is now a more pressing need to be accessible and do well in school.
Junior high school teaches the standard subject matter only and focuses more on information processing, which includes more rigorous testing methods, and more involved cognitive and memory development. Middle school, on the other hand, assists in helping the student with their personality and emotional development.
In middle school, the higher grades must share the building with the younger children, which can be rather tedious for the kids who are growing up quickly. In middle school, teachers tend to be more team oriented. While in high school, teachers are independent of each other.