Sexual orientation describes patterns of sexual, romantic, and emotional attraction—and one's sense of identity based on those attractions. Sexual orientation is distinct from gender identity, the internal sense of being male, female, or non-binary.
Heterosexuality (attraction to members of the opposite sex), homosexuality (attraction to members of the same sex), and bisexuality (attraction to members of both sexes) are the three most commonly discussed categories of sexual orientation, although they are by no means the only ones in the world of sexual identification.
The designation queer, for example, is used by some for its non-specificity to sexual orientation and gender identity, and acts as an umbrella term for non-heterosexual, cisgender individuals. Pansexual and omnisexual are terms gaining currency as the binary division of gender itself is called into question in some subcultures.
While most scientists agree that nature and nurture both play complex roles, the determinants of sexual orientation are still poorly understood. Current research frequently focuses on the role of genes, environment, brain structure, and hormones.