Definitions of sexual orientation depend in part on who, and when, you ask. For most of our history sexual orientation didn’t exist as it does today. People talked about and were identified by which sexual behaviors they engaged in, not who they did them with.
Today the common definition of sexual orientation is a medical one and refers to the direction of your sexual interests. If you are primarily attracted to people of the same gender you're considered gay or lesbian; if you're primarily attracted to people of an opposite gender you’re straight or heterosexual. If your attraction is to two genders you are considered bisexual.
Recently activists and a few researchers have proposed a new orientation, asexual.
Some researchers argue that sexual orientation is an either/or proposition, meaning most of us fit into one category or another. Others believe that orientation is on a continuum, that our sexual interests are varied and may not always be pointed in one direction.
Of course individuals rarely fit neatly into categories like these, and there are problems with this conception of sexual orientation. For starters, there aren’t only two genders to choose from. People identify themselves as transsexual or transgender, some people feel there is no single gender term or identity that fully describes how they feel and what they do in the world. The medical definition doesn’t provide flexibility for that. Also, there are people who are strongly attracted to one gender, but sometimes like to have sex with people of another gender.
Sexual orientation may be helpful to think about, but from a sexual health perspective it’s less important to be one orientation or another than it is to be having sex, and sexual relationships that are by choice and with the people you want to be with.
