Feminism is a collection of movements aimed at defining, establishing, and defending equal political, economic, and social rights and equal opportunities for women. Its concepts overlap with those of women's rights. Feminism is mainly focused on women's issues, but because feminism seeks gender equality, some feminists argue that men's liberation is therefore a necessary part of feminism, and that men are also harmed by sexism and gender roles. Feminists are "person[s] whose beliefs and behavior[s] are based on feminism.