The Moon is called a natural satellite of the Earth because it is a celestial body that orbits around the Earth. A satellite, in the context of astronomy, refers to any object that revolves around a larger body in space. While artificial satellites are human-made objects that orbit planets, natural satellites, also known as moons, are naturally occurring objects that orbit planets or other celestial bodies.
The Moon specifically is Earth's only natural satellite. It orbits the Earth in an elliptical path, influenced by the gravitational pull between the two bodies. The Moon's gravitational interaction with the Earth results in various phenomena such as tides and the stabilization of Earth's axial tilt, which plays a crucial role in the planet's climate and seasons.
The term "natural satellite" distinguishes the Moon from human-made satellites, which are intentionally launched and placed into orbit around celestial bodies for various purposes like communication, weather monitoring, scientific research, and more.