What is the difference between gravitational potential energy and gravitational field strength?

Gravitational Potential Energy is the work done in moving a mass from infinity to a point in a gravitational field. On the other hand, Gravitational Field Strength is the force exerted per unit mass on a small test mass. They seem quite similar at first, however GPE is the energy an mass (object) placed in the magnetic field has, while GFS is the force a mass's gravitation field exerts at a certain point.