The word 防守 is formed by combining two characters, each contributing a core action to create a unified concept. 防 (fáng) depicts the idea of creating a barrier or taking preventative measures, like an embankment against a flood. 守 (shǒu) conveys the act of guarding, watching over, and holding a position. When joined, they sequentially depict first establishing a defensive perimeter or barrier (防) and then actively maintaining and guarding it (守), together forming the comprehensive action of "to defend".