top four schools; schools of the upper quartile
Refers to the four highest-ranked schools in a given ranking context, often in academic or competitive settings. The term is a specific compound and not a general description.
Competition among the top four schools in this region is fierce every year.
He was accepted into one of the top four schools.
上位 means 'upper rank' or 'top' in general, while 上位四校 specifically refers to the top four schools.
Compound of 上位 (upper rank) + 四 (four) + 校 (school). The exact historical derivation is uncertain; it is a straightforward modern compound.