A gravity well is a concept used in physics to describe the gravitational field around a massive object, like a planet or a star. It illustrates how gravity pulls objects toward the center of the mass. The deeper the well, the stronger the gravitational pull, making it harder for objects to escape. In a visual sense, you can imagine a gravity well as a funnel or a bowl, where the sides represent the gravitational force. Objects like satellites or spacecraft must reach a certain speed, known as escape velocity, to break free from the well's pull and travel into space.