Aesthetic attraction: “I want to look at you.” You think someone is beautiful, very pleasing to the eye, but you feel no desire to touch them.
Sensual attraction: “I want to cuddle you.” You feel a great deal of affection towards someone and you want to hug them, hold them, perhaps kiss them, but with your hands never straying below the belt.
Sexual attraction: “I want to fuck you.” You want to do things of an explicitly sexual nature with someone.
Why is this distinction important? Because I didn’t realize I was demisexual until the age of 27 because all my life I thought that aesthetic + sensual attraction was the same thing as sexual attraction. I always thought that finding someone beautiful and wanting to touch or kiss them was sexual attraction, but realizing that it’s not, that sexual attraction means actually desiring sexual acts with a person, has changed my life and explained so many things. When I was figuring this out, a number of other people commented that they felt the exact same as me, so I think this is some pretty important stuff to spread around.
It’s important to know that there are many different types of attraction we can experience as humans. It’s part of what makes our sexual/romantic identities so rich and varied.