What's the difference between justice and revenge?

Justice is being fair or giving punishment that is well deserved to any person. A good example of justice is a police officer arresting a murderer and putting him away in jail for a very long time. Revenge is harming someone who has did something wrong to you. A good example of revenge is a father killing his sons bully, as if seems that both are giving that person what they deserve "revenge is more harsher then justice because you're inflicting pain on that person who has did you wrong, not giving fair treatment to that person."

Hope this helps.