How is the third wave feminism different from first or second wave feminism?
First wave feminism, which lasted from the 1840s to the 1920s, although dealing with women's rights as a whole, was largely just concerned with getting women the right to vote. It also had ties with the Temperance Movement. Second wave feminsim lasted from the 1960s to the 1980s. Its big focuses were on equal opportunity and pay in employment, and reproductive rights.
Third wave feminism arose after the 1980s. What largely differentiated it from the first and second waves, was that third wave feminism attempted to be more inclusive of a wider range of women. First and second wave feminism were both largely movements comprised of white, middle to upper class, able-bodies, cis-gendered, straight women. Although black women and lesbians were significant contributers to first and second wave feminism, they were largely ignored by other feminists, discriminated against within the movement, and asked to value their identity as a woman over any other identities they might posses. Third wave feminism attempts to be more inclusive to different women, and to work on solving issues faced by a wide range of women, and not just problems faced by white, middle-class women.