Tectonic Plates<span>, Earthquakes, and </span>Volcanoes<span>. According to the theory of </span>plate tectonics, Earth is an active planet. Its surface is composed of many individualplates<span> that move and interact, constantly changing and reshaping Earth's outer layer.</span>Volcanoes<span> and earthquakes both result from the </span>movement<span> of </span>tectonic plates<span>.</span>
Hills are easier to climb than mountains. They are less steep and not as high. But, like a mountain, a hill will usually have an obvious summit, which is its highest point. According to the U.S. Geological Survey, there is no official difference between hills and mountains.
On Earth. A small planet in our solar system. Rotating the sun. In a Galaxy we have come to call The Milky Way