I have always thought of G.P.E as how much a constrained body wants to fall in the direction of Gravitational Force Feild.But a while back i came across the concept of Gravitational Binding Energy. The book said that it was the Modulus of G.P.E and it was the energy by which an object is bound to earth. So now do i have to think of G.P.E as the energy by which a object is bound to earth? And why should i supply this much energy to the body as Kinetic energy to separate the body from earth when the only reason its still bound is the Gravitational Force? I am sorry if the question is confusing as i spent few hours thinking of this and got confused.