Parameter Tree:
EARTH SCIENCE > SOLID EARTH > GRAVITY/GRAVITATIONAL FIELD > GRAVITY

Definition:
The natural phenomenon by which physical bodies appear to attract each other with a force proportional to their masses. It is most commonly experienced as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped. The phenomenon of gravitation itself, however, is a byproduct of a more fundamental phenomenon described by general relativity, which suggests that spacetime is curved according to the energy and momentum of whatever matter and radiation are present.

Reference:
NOAA