The ace spectrum is a gray area between asexuality and non-asexuality. Some people say that they occasionally experience sexual attraction, yet still relate to asexuality. The ace umbrella encompasses asexuals, as well as people in this gray area.
Some people, known as “gray-asexuals”, experience sexual attraction infrequently or not very strongly or possibly aren’t quite sure whether or not what they experience is sexual attraction.
One subtype of gray-asexuals, known as “demisexuals”, can experience sexual attraction only after developing a close emotional bond with someone.