Sexual orientation is a pattern of emotional, romantic, and/or sexual attractions to men, women, both genders, neither gender, or another gender. According to the American Psychological Association sexual orientation also refers to a person’s sense of "personal and social identity based on those attractions, behaviors expressing them, and membership in a community of others who share them." Sexual orientation is usually classified according to the sex or gender of the people who are found sexually attractive. Though people may use other labels, or none at all, sexual orientation is usually discussed in terms of three categories: heterosexual, homosexual, and bisexual. These orientations exist along a continuum that ranges from exclusive heterosexual to exclusive homosexual, including various forms of bisexuality in-between. The continuum between heterosexual and homosexual does not suit everyone, however, as some people identify as asexual. Sexologists see this linear scale as an oversimplification of a more nuanced notion of sexual identity.
Most definitions of sexual orientation include a psychological component, such as the direction of an individual's erotic desire, or a behavioral component, which focuses on the sex of the individual's sexual partner/s. Some definitions include both components. Some people prefer simply to follow an individual's self-definition or identity.
Some scholars of sexology, anthropology and history have argued that social categories such as heterosexual and homosexual are not universal. Different societies may consider other criteria to be more significant than sex, including the respective age of the partners, whether partners assume an active or a passive sexual role, and their social status.
Sexual identity and sexual behavior are closely related to sexual orientation, but they are distinguished, with identity referring to an individual's conception of themselves, behavior referring to actual sexual acts performed by the individual, and orientation referring to "fantasies, attachments and longings." Individuals may or may not express their sexual orientation in their behaviors. People who have a homosexual sexual orientation that does not align with their sexual identity are sometimes referred to as closeted.
Sexual identity may also be used to describe a person's perception of his or her own sex, rather than sexual orientation. The term sexual preference has a similar meaning to sexual orientation, but is more commonly used outside of scientific circles by people who believe that sexual orientation is, in whole or part, a matter of choice.
Sexual orientation is a concept that evolved in the industrialized West and there is a controversy as to the universality of its application in other societies/ cultures. As Michel Foucault put it, "'Sexuality' is an invention of the modern state, the industrial revolution, and capitalism." Non-westernized concepts of male sexuality differ essentially from the way sexuality is seen and classified under the system of Sexual Orientation. The validity of the notion of 'sexual orientation' has also been questioned within the industrialized Western society.