
The bisexual flag.
Bisexual defines being attracted to two or more genders, with or without preference. This definition can cover being many different forms of bisexuality, such as being attracted to two genders, being attracted to the same and opposite gender/s and being attracted to all genders. None of these genders have to be binary genders but they often are. It's also sometimes defined as the attraction to genders both the same as and different to one's own. Bisexuality can be used as an umbrella term for other mspec identities if a person decides they feel more comfortable with this. Bisexuality overlaps with other mspec identities in definition (pan, omni & poly) but to refer to these other identities as bisexual is biphobia and erasure of all identities involved.
History[]
Bisexuality has been identified in history as far as in Ancient Greek religious texts, which reflected cultural practices, and had bisexual themes throughout. It was used to define sexuality for the first time in 1892 as a term for attraction to men and women by neurologist Charles Gilbert Chaddock. In the 1940s, Bisexual sexologist Alfred Kinsey developed the Kinsey Scale which shows sexuality as a spectrum from completely heterosexual to completely homosexual, but is against the new usage of "bisexual" to describe this. Bisexual activism (and LGBT activism in general) becomes more prominent in the 1960s which causes the bisexual term to get more inclusive of non-binary and intersex identities. In 1990 the bisexual manifesto gets published and bisexuality is defined as a whole, fluid identity that is not binary or duogamous in nature.
Flag[]
The bisexual pride flag was designed by a team led by LGBT activist Michael Page in 1998. The flag was created in order to give the bisexual community its own symbol which was easily recognized and comparable to the gay pride flag (rainbow flag) that represented the larger LGBT community. Page's aim was to increase the visibility of bisexuals, both among society as a whole, and within the LGBT community.

The bisexual crescent moon symbols.

The Bi-Infinity Symbol
The pink color represents sexual attraction to the same gender, the blue represents sexual attraction to the opposite sex, and the resultant overlap color purple represents sexual attraction to both genders.
Symbols[]

The bisexual triangles- sometimes known as biangles
A symbol used by the bisexual community involves the bisexual crescents (a pair of back-to-back moon crescents) ☽☾ and the bisexual symbol, an infinity symbol featuring the female (Venus) and male (Mars) symbols as well as a blank circle for the genders and attractions between. ⚤
Another symbol of the community are the bisexual triangles. They are sometimes referred to as 'biangles'. The biangles were the first symbol of the community to use the iconic pink, purple and blue colours. It was designed by Liz Nania for the Boston Bi Woman's Community. The biangles take inspiration from the pink triangle symbol, which has been used as a reclaimed symbol for homosexuality originating in Nazi concentration camps. The colours of these triangles later served as the inspiration for Michael Page's bisexual flag.