Why does rhe of Saturns state play Atlas prometheus and Pandora called shepherd moons?

The moons Atlas, Prometheus, and Pandora are referred to as "shepherd moons" because they play a crucial role in maintaining the structure of Saturn's rings. Their gravitational influence helps to confine and shape the ring particles, preventing them from spreading out too much. For example, Prometheus and Pandora create gaps, known as "propeller" features, in the rings due to their gravitational interactions. This shepherding effect keeps the rings well-defined and stable over time.