Updated: DECEMBER 24, 2018
Bisexual is a term used to describe people who are sexually or romantically attracted to both men and women. It may also be used to describe those who are attracted to all sexual and gender identities. Although many people self-identify as strictly hetero- or homosexual, a large percentage of people don't fit into either category and feel attraction to both sexes, either consistently, or in a way that fluctuates throughout their lives.
More About Bisexual
Many people object to the limiting nature of this term and prefer to call themselves pansexual, non-preferential, sexually fluid, ambisexual, or queer. Because bisexuals are such a diverse group, this term can be difficult to define, especially when you consider people who are gender-fluid, or have transitioned from their birth gender to a different gender. These people may identify as genderqueer because the terms heterosexual, homosexual and bisexual are all based on the idea that there are only two genders, male and female.
A final factor is that bisexuality need not be defined by action. In the 1970s, psychiatrist and bisexual rights advocate Dr. Fritz Klein created the Klein Sexual Orientation Grid, which includes sexual fantasies, emotional and social preference, and self-identification as measures of sexual orientation, along with sexual attraction and sexual behavior. This provides a more nuanced view of sexual orientation and attraction.