Question

What is escape velocity?

Answer 1

It is the lowest velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.

Every planet has their own corresponding escape velocities. Example - Earth has escape velocity of 11.2 Km/s. It means, if you want to leave the Earth's gravitational field then it's the lowest speed which you need to acquire otherwise you wouldn't do that!

Hope this helps!