As an asexual, I can answer this one.

Asexuality is where someone doesn't experience sexual attraction, making it an orientation like homo/hetero/bi/etc-sexual. An asexual can still experience a desire for an emotional/romantic relationship with a partner*, they can also have a libido (the basic desire for sexual stimulation, which occurs by itself like hunger, and isn't triggered by the sight or desire of another person) and can still have sexual intercourse, for reasons such as curiosity, peer pressure, compromise with a partner, conception of children, to experience the emotional bond that can come with intercourse, or because they can enjoy the physical sensations involved. So an asexual can still technically have an interest or an enjoyment in sex, but they just are not sexually attracted to their partner. Many others do not desire to have any form of sexual interaction with another person and for those who desire romantic relationships it may be that while sex is an enhancement of a relationship for a non-asexual, the same acts can be damaging to the love of an asexual.

In short, when I look at people, I just see people. Essentially, I experience the same amount of sexual attraction to the same sex as a straight person and the opposite sex as a gay person. That is to say, none. I'm perfectly comfortable with my sexuality. To be honest, any other way seems rather complicated.

*Some people ask "isn't a relationship without sex just a friendship?" Well, by the same logic, a friendship with sex is a relationship. Is that true? Essentially the difference between a friendship and an asexual relationship is like the difference between a loving sexual relationship and "friends with benefits". There's a totally different depth of mental and emotional feelings and understandings involved. An asexual can be perfectly in love without seeing physical acts as anything relating to those feelings, although many of us do of course understand that non-asexuals can see sex as an expression of love and the absence of it is often a "deal breaker".

You are welcome to ask me more questions, or you can visit AVEN, which is the main asexual network.