You can use YW to most age groups as it is just a way of saying You welcome and it has no negative or explicit connotation. The younger children might need instruction on when to use slangs and when to use complete sentences. It is important to teach them the appropriate digital etiquette to guarantee that they will communicate respectfully. Among teens, YW is popular and acceptable. Parents need not be concerned with the word, but their general internet demeanor and attitude. Know more about what does yw mean