The Moon Eclipses the Sun
An eclipse of the Sun happens when the New Moon moves between the Sun and Earth, blocking out the Sun's rays and casting a shadow on parts of Earth.
The Moon's shadow is not big enough to engulf the entire planet, so the shadow is always limited to a certain area. This area changes during the course of the eclipse because the Moon and Earth are in constant motion: Earth continuously rotates around its axis while it orbits the Sun, and the Moon orbits Earth. This is why solar eclipses seem to travel from one place to another
Watch Solar Eclipses