Asexuality is a sexual orientation describing individuals who do not experience sexual attraction.
Note that asexuality is not the same as celibacy, which is the deliberate abstention from sexual activity; many asexuals do have sex,and most celibates are not asexual.
Asexuals may experience romantic attraction, or the desire for, fantasy of, or propensity towards romantic love , often directed at people of genders falling within an affectional orientation. Many asexuals also identify as straight, gay, or bi, using the terms in a strictly affectional sense, or alternatively as hetero-, homo-, or bi-romantic. Some asexuals identify as "aromantic." A relationship between an asexual and a sexual person may or may not involve sexual activity.
Affectional orientation (or romantic orientation) is an alternative term for sexual orientation. It is based on the perspective that sexual attraction/desire is but a single component of a larger dynamic. To holders of this view, one's orientation is defined by whom one is predisposed to fall in love with, whether or not one desires that person sexually.
Lately, the predominant use of the term "sexual orientation" is considered to reduce a whole category of desires and emotions, as well as power and connection, to sex.
The term affectional orientation is also used by those who consider themselves asexual and only feel emotional and/or physical (aesthetic) attraction. The terms used for different affectional orientations are usually the same as those for sexual orientations; though "homoromantic", "biromantic," "heteroromantic," and "aromantic" have gained some popularity. Asexuals sometimes incorporate colloquial terms to describe both the romantic and sexual components of their orientation (e.g. gay-asexual, bi-asexual, and straight-asexual).
(from AVENA-Asexual Visibility and Education Network)
Many asexual people experience attraction, but we feel no need to act out that attraction sexually. Instead we feel a desire to get to know someone, to get close to them in whatever way works best for us.
Some asexuals express intimacy through talking, maybe sharing their innermost fears and secrets or by making each other laugh. Some asexuals feel intimacy with their partners by sharing common interests and activities or by working together toward common goals.
For some sexual arousal is a fairly regular occurrence, though it is not associated with a desire to find a sexual partner or partners. Other asexual people experience little or no arousal.
There is no litmus test to determine if someone is asexual. Asexuality is like any other identity- at its core, it’s just a word that people use to help figure themselves out.
Asexuals can be 'more than friends' or even consider their relationships 'closer than lovers'
Is it possible to be asexual as well as lesbian, gay, or bi?
Yes, it is. Asexuals do not experience sexual attraction, but some experience romantic attraction, which can be directed towards either or both sexes.