Asexuality is the lack of sexual attraction to anyone, or low or absent interest in or desire for sexual activity. It may be considered the lack of a sexual orientation, or one of the variations thereof, alongside heterosexuality, homosexuality and bisexuality.
Asexuals are generally very different from one another: some experience romantic attraction, some don’t. Some experience arousal, some don’t.
Asexuality is not celibacy – celibacy is a choice to abstain from sexual intimacy while asexuality is an orientation which results in lack of sexual attraction.
NEW: Here is an informative YouTube video on the Subject.