Gay refers to the attraction towards or desire for the same gender (or similar genders to one's own). Terms such as homosexual and homoromantic can be considered synonyms or subcategories of gay.
While the term gay can apply to men, women, and non-binary individuals, it is sometimes used to only refer to gay men. The term lesbian tends to be used specifically for gay women. Less commonly, other terms such as vincian are used specifically for gay men. Gay has also been used as an umbrella term for anyone who is non-straight, or anyone in the LGBTA+ community.
The earliest documentation of same-sex relations in the western world is that from ancient Greece. Relations between adult men and adolescent boys were valued as a form of population control.
Ancient Rome took many of its ideas on sexuality from ancient Greece. Many Roman men partook in bisexual behavior. All emperors, with the exception of Claudius, had male lovers until the Christian emperor, Theodosius I decreed a law condemning gay men to be burned at the stake, in 390.
During the Renaissance cities such as Florence and Venice were known for the widespread practice of same-sex relations. However, the authorities were prosecuting, fining, and imprisoning much of the gay population.
Along with woman's rights and the civil rights movement, the gay rights movement has been brought to the forefront of society in the last century.
In June 2015 the U.S. Supreme Court ruled that the right of same-sex couples to marry is on the same terms and conditions as opposite-sex couples, making same-sex marriage legal in all states.
The rainbow flag was originally decided by Gilbert Baker and was first displayed in a Gay Freedom Day Parade celebration on June 25, 1978. The flag represents the entire LGBT community, but is commonly used to represent gay individuals specifically. The original flag had eight stripes, with each stripe having a specific meaning: hot pink - sex, red - life, orange - healing, yellow - sunlight, green - nature, turquoise - magic/art, indigo - serenity, violet - spirit.
This design has undergone some changes over the years. As the demand of rainbow flags increased they began selling with seven stripes, without the pink stripe due to the lack to pink fabric. In 1979 the design was changed again because, when hung vertically from the lamp posts of San Francisco's Market Street, the center stripe was obscured by the post itself. The turquoise stripe was dropped, making a flag with an even number of stripes.
The first known use of the term homosexual is found in an 1869 German pamphlet by the novelist Karl-Maria Kertbeny. The word is derived from the Greek prefix homo- meaning 'same'. Many modern sources advise against using the term homosexual, and to instead use gay, due to the fact that homosexual has a history of being used negatively and in clinical context.
The term gay originally meant 'happy', 'carefree', or 'cheerful'. It was occasionally used to refer to homosexual men in the 19th century, but lost popularity in the beginning of the 20th century. The term was solidified in in 1960's when homosexual men began using it to describe their orientation.