Why is there a hole in the lid of the teapot?

The hole in the teapot cover is not for heat dissipation, but to keep the pressure inside and outside the teapot consistent. If there are no holes in the lid of the teapot, a certain vacuum will be formed in the teapot when we pour water. At this time, because the air pressure outside the teapot is greater than the pressure inside the teapot, the water can't be poured at the spout because the inward pressure is greater than the outward pressure. By adding a small hole in the lid of the teapot, the air inside and outside the teapot is kept in communication, which balances the air pressure inside and outside the teapot and solves the problem that water cannot be poured when the air pressure inside the teapot is less than that outside the teapot.