What does it feel like to be sexually attracted to someone?

Hi everyone! I've been questioning my sexuality lately. For the most part, I've always believed that I was bisexual, but lately I have wondered if I'm somewhere on the ace spectrum as well. I'm mostly having trouble distinguishing between aesthetic and sexual attraction because I always thought they were the same thing. I was hoping that you guys can give me more straightforward answers because when I read posts in other subreddits, they are too vague for me to understand. So, for those that do feel sexual attraction, is it instantaneous? Do you feel it towards strangers? What thoughts go through your head? Do you feel compelled to act on those feelings? How often does it happen? Also, when it comes to sex, is it something that you need on a regular basis, or is it something you could go without? Feel free to add any more details as well if you are comfortable doing so. Thank you!