Final answer:
Einstein's Theory of General Relativity redefined gravity as the warping of space-time caused by mass, differing from Newton's view of gravity as a force between masses. Einstein's theory accounts for phenomena Newton's could not, like the precession of Mercury's orbit and light bending around massive objects, and is vital to modern physics and cosmology.
Step-by-step explanation:
Einstein's Theory of General Relativity, proposed in 1916, introduced a revolutionary concept that gravity is not a force pulling objects together, as Newton's Law of Universal Gravitation suggested, but rather a curvature of space-time caused by the presence of mass. While Newton's model provided incredibly accurate predictions within our solar system, it couldn't account for certain phenomena, such as the precession of the orbit of Mercury, nor could it describe the behavior of light in a gravitational field, which was observed as light bending around massive objects like the sun during a solar eclipse. Einstein's theory has been experimentally verified many times, with predictions such as the bending of starlight during the 1919 eclipse and the more recent observation of gravitational waves from colliding black holes.
The differences between Newton's and Einstein's gravity become particularly significant in strong gravitational fields, such as near black holes, where the predictions from general relativity must reconcile with effects not apparent in Newtonian physics. Nonetheless, in most everyday situations, Newton's laws remain an excellent approximation. However, general relativity goes beyond, explaining complex gravitational interactions, and is a cornerstone of modern physics, leading to concepts like black holes and the potential unification of forces into a Theory of Everything (TOE).