Is middle school and jr high the same?

Answer 1

No, they're not, though there may be some overlap.

A "middle school" is a school serving students older than those in the elementary school, but not as old as those in the high school. It's often 4th-6th grade, but in some cases may be other grade ranges.

Jr. High is usually taken to mean 7th and 8th grade, regardless of where they physically attend school. Large school districts may have a separate Jr. High campus, or they may be combined with the Middle School, the High School, or both. Freshmen (9th grade) is somewhere in a kind of "limbo" state: in many states, 9th graders cannot compete at either the Junior High or High School levels, and have their own separate sports teams.

My own middle school was 5th-7th grade. 7th graders were considered "Jr. High" despite attending the (physical) middle school, and would take buses after school from there to the high school campus for Jr. High sports practices (where they were combined with the 8th graders, who went to school in a wing of the High School building).