Earth's motion can be described in two main ways: rotation and revolution. The planet rotates on its axis, which is an imaginary line that runs from the North Pole to the South Pole. This rotation takes about 24 hours, causing day and night as different parts of the Earth face the Sun. In addition to rotation, Earth also revolves around the Sun in an elliptical orbit. This revolution takes approximately 365.25 days to complete, which defines one year. The tilt of Earth's axis during this revolution is responsible for the changing seasons, as different areas receive varying amounts of sunlight throughout the year.