A gravitational field is a region around a mass where other masses experience a force of attraction. This concept helps explain how objects like planets, stars, and moons interact with each other. The strength of the gravitational field depends on the mass of the object creating it and the distance from that object. For example, the Earth has a strong gravitational field that keeps us and everything else on its surface. Similarly, the Moon has its own gravitational field, which affects the ocean tides on Earth. Understanding gravitational fields is essential in fields like astronomy and physics.