How many types of peace are there?

Talk of "peace" has been around for millennia. People have always tried to find the formula for lasting peace. Every war (increasingly bloody and cruel) brought people to the same question: how can lasting peace be achieved? 

Tens of thousands of pages preserve in the world's libraries the thoughts and systems of thought of numerous philosophers who have endeavoured to find an answer to this eternal question. 

Political scientists have followed in these philosophers' footsteps for more than a century. They created theories designed to describe, explain, or even predict the behaviour of nations that lead to war.