GLBT- an abbreviation for gay, lesbian, bisexual, and transgendered, usually referring to the community as a whole.

sexual orientation- a person’s emotional, physical, and/or sexual attraction and the expression of that attraction. Although a subject of debate, sexual orientation is probably one of the many characteristics that people are born with. Most people become aware of their sexual orientation during adolescence. 

homosexuality - A sexual orientation in which a person feels physically and emotionally attracted to people of the same gender. 

heterosexuality - A sexual orientation in which a person feels physically and emotionally attracted to people of the opposite gender. 

bisexuality - A sexual orientation in which a person feels physically and emotionally attracted to people of both genders. 

transgender - The experience of having a gender identity that is different from one's biological sex. A transgender person may identify with the opposite biological sex and want to be a person of that gender. 

sexual minority - A person who may identify as homosexual, gay, lesbian, bisexual, transsexual, transgender, or transvestite. All gays and lesbians are members of a sexual minority, but not all 
sexual minority persons are gay. 

“coming out" - Also, "coming out of the closet" or "being out," this term refers to the process in which a person acknowledges, accepts, and in many cases appreciates her or his lesbian, gay, or bisexual identity. This often involves the sharing of this information with others. The process of coming out to oneself and to others occurs for different young people (and adults) in a variety of places and ways. 

homophobia - The fear, dislike, and hatred of same-sex relationships or those who love and are sexually attracted to those of the same sex. Homophobia includes prejudice, discrimination, harassment, and acts of violence brought on by fear and hatred. It occurs in schools on personal, institutional, and societal levels. 

internalized homophobia - The fear and self-hate of one's own homosexuality or bisexuality that occurs for many gay and lesbian individuals who have learned negative ideas about homosexuality throughout childhood. Once gay and lesbian youth realize that -they belong to a group of people that is often despised and rejected in our society, many internalize and incorporate the stigmatization of homosexuality and fear or hate themselves. 

heterosexism - The assumption that all people are or should be heterosexual. Heterosexism excludes the needs, concerns, and life experiences of lesbian, gay, and bisexual people while it gives advantages to heterosexual people. It is often a subtle form of oppression which reinforces realities of silence and invisibility for gay and lesbians. 

invisibility - The constant assumption of heterosexuality renders gay and lesbian people, youth in particular, invisible and seemingly nonexistent. Gay and lesbian people and youth are usually not seen or portrayed in society, and especially not in schools or classrooms.