What is a triple star?

Answer 1

A triple star is a group of three stars orbitting each other. It's called that way, even though it should be called a triple star system.

Answer 2

A triple star system is a system of three stars that are gravitationally bound to each other and orbit around a common center of mass. Triple stars can either be hierarchical, where two stars are closer to each other and the third is more distant, or trinary, where all three stars are relatively close to each other. Triple stars are relatively rare compared to binary stars.