A homosexual is a person who is predominantly sexually attracted to people of the same sex. The word homosexual may be used as both a noun (e.g., "We are homosexuals.") and an adjective (e.g., "We are homosexual people."). Male homosexuals are often called gay, and female homosexuals are often called lesbian.
Not everyone that is attracted or has sexual relationships with members of the same sex identify themselves as homosexual or even bisexual. Some people frequently have sex with members of the same sex yet still see themselves as heterosexual. It is important therefore to distinguish between homosexual behaviour, homosexual attraction and homosexual identity, which need not coincide.
Queer theory, and most famously the French philosopher Michel Foucault (though some have argued that his opinions on this issue have been distorted by later scholars), attacks the notion that sexual identities such as 'homosexuality', 'heterosexuality' or 'bisexuality' have any objective existence, as opposed to being a social construction. A frequent argument used is that homosexuality prior to the modern period was different from modern homosexuality (age-, gender- or class-structured rather than egalatarian). Critics argue that, although homosexuality in different periods has had different features, the underlying phenomena has always existed and is not a recent invention of our society.
To varying degrees, at least until relatively recently, Judaism, Christianity and Islam have always assumed that sexual orientation was a matter of choice, and that to choose homosexuality was an abomination. Homosexual acts were always considered sinful, and in theory the Tanakh (The Hebrew Bible) prescribes the death penalty for anyone who engages in such an act. This harsh sentence is mitigated by the fact that, in theory, the Tanakh prescribes the death penalty for a great number of acts, yet in practice Jewish law outlawed the death penalty in almost all cases more than 2000 years ago. Further, the Tanakh describes a great many acts as "abominations" including the eating of unkosher meat, or shellfish. Religion and homosexuality turns out to be a fairly complex topic, and thus deserves an entry of its own.