The Earth rotates around an imaginary axis called the rotational axis. This axis runs through the Earth from the North Pole to the South Pole and is inclined at an angle of approximately 23.5 degrees relative to the plane of its orbit around the Sun. This tilt is what gives rise to the changing seasons on Earth as different parts of the planet receive varying amounts of sunlight throughout the year. The rotation of the Earth on its axis is what causes day and night.