When parents, teachers, and friends say that, they are asking you to be attentive. Attentiveness is being mindful of another's speech, actions, or needs. It's not just hearing, it's listening; it's not just seeing, it's noticing. When you are attentive to another person, you are showing that you care about what he or she is saying or doing. The opposite of attentiveness is heedlessness.
Lack of attentiveness can cause hurt feelings. Imagine that you are talking with a friend. Rather than look at you, this friend nods while glancing around. You get the idea that you aren't important. Your friend is only talking to you until someone more interesting comes along. Ouch!
Many parents complain about the lack of attentiveness at chore time. A son or daughter is reading or watching TV or playing a video game. The parent tells the child to do a chore. The child nods without looking up, and chances are that he or she will not remember agreeing to do the chore.