Sexual Orientation or Sexuality is a term, or group of terms, that refers to the gender(s) one feels sexual attraction to and/or how one feels sexual attraction. Typically, sexual orientation labels are derived using a prefix combined with the suffix "-sexual." For example, asexual, bisexual, heterosexual, and demisexual are all examples of sexual orientations. Other labels that do not use the "-sexual" suffix, such as gay, lesbian, trixic, etc, can also be used to describe one's sexuality.
The romantic counterpart is romantic orientation. For most perioriented people sexual orientation is the only label used, as one's romantic orientation can be assumed to be the same unless specified otherwise. Though, for ace-spec, aro-spec, or otherwise varioriented people it is often useful to identify with separate sexual and romantic orientations.