The Earth is a planet in the solar system that revolves around the sun and rotates on its axis. It has three main components - the atmosphere, hydrosphere, and geosphere. The atmosphere contains gases and surrounds the planet. The hydrosphere is made up of all water on Earth, found mainly in oceans. The geosphere consists of solid elements in three layers - crust, mantle, and core. The Earth's rotation causes day and night and its revolution around the sun causes the seasons. Maps represent the Earth's surface and use techniques like cartographic projections to depict the spherical planet on a flat surface.