The main driving power or motivating force behind something; the primary cause that propels action or progress.
若者の起業が地域経済の原動力になっている。
Young entrepreneurs are becoming the driving force of the regional economy.
彼の好奇心が研究の原動力だ。
His curiosity is the driving force behind his research.
新技術は業界革新の原動力となった。
New technology became the driving force for industry innovation.