What is "senior high schools"

Usage examples of "senior high schools".

Margaret White was born and raised in Motton, a small town which borders Chamberlain and sends its tuition students to Chamberlain's junior and senior high schools.

In grade school and, later, junior and senior high schools, I was often tardy or truant, drawn to the lowlife students, in part because they represented my own defiance and belligerence.