Gravitational energy is energy that is stored or released due to gravity. Gravity is a force that pulls things towards each other, like how the Earth pulls things towards it. Everything that has mass, like people or planets, creates a force of gravity.
When two things with mass are close together, they have potential energy because they could move closer to each other due to gravity. Think of it like a ball on top of a hill - it has potential energy because it could roll down the hill. Similarly, objects with mass can have potential energy because of gravity.
When two things with mass move closer together, they lose some potential energy and gain kinetic energy (energy of motion). This is because gravity is a force that causes things to move towards each other.
An example of gravitational energy can be seen when you drop a ball from your hand. As the ball falls towards the ground, it loses potential energy and gains kinetic energy.
Gravitational energy is very important in space - it helps keep planets in orbit around stars and moons in orbit around planets. The gravitational energy between the planets and their moons is what keeps them moving in a predictable and stable orbit.
In summary, gravitational energy is a type of potential energy that objects with mass have when they are near each other due to gravity. When these objects move closer together, they lose potential energy and gain kinetic energy.