I, personally, didn't even know that Asexuality was a thing until one of my close friends came out to me as Asexual and brought its awareness into my school's Queer Straight Alliance. Though it seems pretty clear to me now, I've realized that a lot of people still really don't know about asexuality and that there are a LOT of misconceptions about it. I've recently come across a video on Youtube, by Laci Green, that talks about asexuality and breaks it down for those of us who've never heard of it before, and so I'm sharing the knowledge! Laci Green is known on Youtube for her sex positive channel that is geared toward providing humorous sex education that covers topics that aren't usually covered in most high school programs.
The video on Asexuality is linked here, and I encourage you to check it out as well as the rest of Laci's channel!