Peer education is something when you study with 'peers' among them and you folks utilize your energies in a positive way, your strengths cover up your weaknesses. It is good and shall be there.
Peer pressure is a feeling and a pressure to compete with 'peers' and it often leads to depression and other things. It can be bad very often. Spirit of competition is fine but when it exceeds the sane limit, it is bad.
There's a MAJOR difference. One is when your peers tell you that drugs are cool, and the other is when your friends educate you that drugs are cool. Now that you see the difference, middle school will be a lot less confusing!