Combining 妇 (adult/married woman) and 女 (woman/female) creates a compound noun that encompasses all adult women, lending it a sense of formality and completeness.
The term 妇女 (fùnǚ) is deeply embedded in the social and political history of modern China. Its most powerful association is with the Communist Party's efforts to promote gender equality after 1949. The famous slogan “妇女能顶半边天” (fùnǚ néng dǐng bànbiāntiān), meaning “Women can hold up half the sky,” was popularized by Mao Zedong. This phrase empowered generations of women to enter the workforce and participate in public life, and 妇女 was the term used to champion this movement. Consequently, the word carries a strong, dignified, and slightly political or official tone. In comparison to Western culture, the English word “women” is a general-purpose term used in nearly every context, from casual to formal. 妇女 (fùnǚ), however, is much more specific to formal contexts. Using it in casual conversation would be like using the term “females” in a sociological report to talk about your friends—it's grammatically correct but socially awkward and impersonal. This highlights the Chinese language's rich vocabulary for specifying formality and social relationships.