Earth's rotation

Earth rotates, or spins, on it's axis. The axis is an imaginary line that runs through the middle of the Earth from the North Pole to the South Pole. Earth spins like a top and takes 24 hours to make one complete spin. This spinning is what causes day and night. When the side of Earth facing the sun is lit up by the sun it is day-time, and when the side of Earth facing away from the sun is in darkness it is night-time.