Well, if I look at someone and find that person physically attractive, it would be infatuation. This is just a quick attraction towards the person. And can happen without even knowing the person. You can get attracted to someone's appearance, the way they walk or talk, the way they smile or laugh etc.
But when you get to know a person, after spending time with them and knowing about them, you'll then start liking them. This is different than just attraction.
As far as I can say, this is the biggest difference between just attraction and actually liking or loving a person.