What is a spinning planet?

Answer 1

Due to centrifugal forces from the spinning, the planet becomes a bit flatter at the poles and wider around equator.

For Earth, the diameter at equator is about 0.5% larger than the diameter through the poles, so the effect is not very big.

Answer 2

The spin of the Earth is the cause of the cycle of daylight and darkness,

and of the rotation of weather systems.

The rotation of the Earth also slow down the Moon's orbital period, causing at the long term significant perturbations in the orbit of the Moon, leading to a larger major axis orbit around the Earth.

Please note this is feedback process, the Earth and Moon's motions are therefore quite complex.

Answer 3

All planets rotate on their axis and also revolves around the Sun, if that's what you mean.