Liking someone infers you already know them. Being attracted to them infers you don't know them.
Iff you feel atracted to someone it's like feeling the need to be with them or them getting your attention but if you like someone you have feelings for them
Liking them means you have feelings for them and their personality, whereas atraction means your enticed by the way they look. Well, at least thats what I think...
Liking someone could mean you like them as a friend...a person. Being attracted to them means you would like to get to know them better and maybe have a relationship w/them.