Earth Orbit And Day And Night

 
Earth is always moving. Each day, the Earth makes one complete rotation on its axis. The axis is the imaginary line through the earth that extends from the North Pole to the South Pole.
As Earth rotates, it seems like the sun is moving across the sky, but it's really the Earth that is spinning. It takes 24 hours to complete one rotation, which is why there are 24 hours in one day.