Celibacy and asexuality are not the same thing.
Celibacy is a behavior, it describes one’s actions. A celibate person does not have sex.
Asexuality is an orientation, it describes one’s attractions. An asexual person does not experience sexual attraction.
It’s possible for a celibate person to experience sexual attraction and simply not act on it. It’s possible for an asexual person to have sex, even though they don’t feel any attraction to do so. And it’s possible for a person to be both celibate and asexual, where they don’t have sex, nor do they experience sexual attraction.
I explore more of the differences in this post.