Used to describe people attracted to the same sex, though lesbian is the more common term for women.
Include sexual orientation only when it is pertinent to a story, and avoid references to sexual preference or to a gay or alternative lifestyle.
Gays is acceptable as a plural noun when necessary, but do not use the singular gay as a noun. Lesbian is acceptable as a noun in singular or plural form.
Avoid identifying gay people as homosexuals, an outdated term considered derogatory and offensive to many lesbian and gay people.
(Source: AP Stylebook, GLAAD Media Reference Guide)