Newton gave a systematic description of gravity and three laws of motion in his paper "Laws of Nature" published in 1687. These descriptions laid the scientific view of the physical world in the next three centuries and became the basis of modern engineering.
In mechanics, Newton expounded the conservation principle of momentum and angular momentum, and put forward Newton's three laws of motion and the law of universal gravitation.
In optics, he invented reflecting telescope, and based on the observation that a prism diverges white light into the visible spectrum, he developed the color theory.
In mathematics, Newton and Leibniz shared the honor of establishing calculus. He also proved the generalized binomial theorem and put forward Newton's method to approximate the zero point of function, which contributed to the study of power series.
Newton is by far the greatest physicist in the world (no one).