The word 服役 is formed by combining two characters, each contributing a key concept: 服 (fú), which carries the core idea of serving or submitting to a duty, and 役 (yì), which specifically denotes compulsory labor or military service. Their combination conceptually blends the act of "serving" with the domain of "compulsory service", most commonly understood as serving in the military or fulfilling a mandated term of service.