Escape velocity is the minimum speed an object needs to escape the gravitational pull of a celestial body, like a planet or a star. It's the speed where the object's kinetic energy (energy of motion) is equal to its gravitational potential energy.

Here's a breakdown:

* Kinetic Energy: The energy an object possesses due to its motion.

* Gravitational Potential Energy: The energy an object possesses due to its position in a gravitational field.

To escape, the object's kinetic energy must be greater than or equal to the gravitational potential energy it has at the surface of the celestial body. This ensures the object will keep moving away and not fall back.