Temporal power refers to the authority or power that the Pope, who is the leader of the Catholic Church, holds in worldly or secular matters, such as governing territories, making laws, and enforcing them.
Imagine you and your friends playing a game. One of your friends is the "boss" of the game, and they get to make the rules and tell everyone what to do during the game. Well, the Pope is kind of like the boss of the Catholic Church.
But the Pope doesn't just have power over the Church itself. In the past, some Popes also ruled over actual lands, like countries or territories. This meant they had power over things like taxes, army, and other things that governments have power over.
Nowadays, the temporal power of the Pope is mostly symbolic, meaning it represents something rather than actually having the power to do things in the world. But back in the past, the Pope's temporal power was very real and had a big impact on people's lives.