A breach of peace is a situation where someone does something that makes other people feel unsafe, or causes a disturbance. It can happen in lots of different ways, like shouting, fighting, or breaking things.
Just like how we have rules at home to make sure everyone is safe and happy, people and communities have rules (laws) to keep everyone safe and happy too. This means that people who breach the peace and break these rules can get in trouble with the police or other authorities.
So, to keep ourselves and others happy and safe, we need to follow the rules and be kind to each other. If someone breaks these rules, they might get in trouble with the law.