| Term | Definition |
| lithosphere | the rocky surface of the Earth |
| atmosphere | the pocket of air that surrounds the earth |
| hydrosphere | all the water on the surface of Earth and underground, including ice and water vapor |
| axis | an imaginary line running from the North Pole to the South Pole through the center of the Earth |
| rotation | the spinning of a planet or moon on its axis |
| orbit | the path one object takes around another object in space |
| tide | the rise and fall of the water level of the ocean near the shore that is caused by the pull of gravity of the moon |