Communal violence is when groups of people fight each other because of their religious or cultural beliefs. It is like two teams who don't like each other, but instead of playing a game, they get into a big fight. They may use weapons, like sticks and guns, to hurt each other and damage each other's property, like houses and cars. This can be very dangerous and can even lead to people getting killed. Unfortunately, it happens all over the world and it's important to try and stop it.