How do tariffs work to protect a nation's industry and goods manufacturing?

Tariffs are usually levied by domestic governments to protect new industries against foreign competition, to protect aging industries against foreign competition, to protect against foreign companies offering their products for a price lower than their costs and to raise revenue

i dont know sorry, but ik that you need to pay attention in class

i think it was because of how protected egyptian civilization was was which allowed them to evolve without much outside influence.