Sexual orientation is an individual pattern of emotional, physical and romantic attraction to people of specific genders or irrespective of their genders. Some of the sexual orientations are bisexuality, pansexuality, asexuality among others. People can sometimes refer to their sexual orientation as queer because they don't resonate to being heterosexual.
Sources:
https://www.hrc.org/resources/sexual-orientation-and-gender-identity-terminology-and-definitions