Have you ever played a game with someone and lost? I bet it made you feel pretty sad and maybe even angry. Well, a long, long time ago, there were two groups of people - the Romans and the Carthaginians - who were fighting against each other in a big war. After a lot of fighting, the Romans won and the Carthaginians were very sad and angry because they had lost.
The Romans wanted to make sure that the Carthaginians would never try to fight them again, so they made something called the "Carthaginian Peace." This means that the Carthaginians were not allowed to have any more soldiers or ships or weapons to fight with. They also had to pay a lot of money to the Romans every year for many years. This made the Carthaginians very poor and weak, and they couldn't fight the Romans anymore.
So, the Carthaginian Peace was a way for the Romans to make sure they were the winners and would stay in power. It wasn't very fair for the Carthaginians, but that's how war works sometimes.