Peer pressure can be either positive or negative, and come from internal or external sources. The document discusses four types of peer pressure: 1) internal positive pressure which is self-motivation to do something beneficial, 2) internal negative pressure which is feeling internal pressure to do something harmful to fit in, 3) external positive pressure such as friends encouraging good behaviors, and 4) external negative pressure involving outside influence to make harmful choices. Examples are provided to illustrate the different types.