Demisexuality is a term used to describe individuals who rarely experience primary sexual attraction – a type of attraction that is based on immediately observable characteristics such as appearance or smell, and is experienced immediately after first encounter. A demisexual person generally tends to develop sexual attraction after they experience secondary sexual attraction – a type of attraction that occurs after development of an emotional bond. The amount of time that a demisexual individual needs to know another person before developing sexual attraction towards them varies from person to person. Demisexuality is generally categorized on the asexuality spectrum.