Ace is where you don’t want a sexual relationship so like fluff not smut and most people use it as an umbrella term for Ace, some Aro etc. if I got something wrong please tell me!
Asexuality is the lack of sexual attraction. It's a spectrum, So, some aces may want a sexual relationship, they just don't particularly lust for it.
Some aces may also not be comfortable with fluff, or physical affection (which is what I interpret 'fluff' as) while others may love being cuddly. I don't think ace should ever be used as an umbrella term for aro, because some aros may still feel sexual attraction, just like some aces still feel romantic attraction, as they aren't aro.
Thanks and sorry that was so bad I’m kinda a shit at rembering things so I just pulled what I remember out of my mind and put it there and I’m so sorry…..