Isaac Newton didn't really "invent" anything in the way we think of inventions like the telephone or the light bulb. He was a mathematician, physicist, astronomer, alchemist, and theologian who made groundbreaking discoveries and developed fundamental concepts in mathematics, physics, and astronomy. Here are some of his most significant contributions:

* Calculus: Newton and Gottfried Wilhelm Leibniz independently developed calculus, which is a powerful tool for studying change and motion. Newton's work on calculus laid the foundation for modern mathematics and physics.

* Laws of Motion: Newton formulated the three laws of motion, which are still fundamental to our understanding of how objects move. These laws explain gravity, inertia, and the relationship between force and acceleration.

* Law of Universal Gravitation: Newton discovered the law of universal gravitation, which explains the force of attraction between any two objects with mass. This law helped explain the motion of planets around the sun and the tides.

* Binomial Theorem: Newton generalized the binomial theorem, which provides a formula for expanding powers of binomials (expressions with two terms).

* Newton's Method: This is a numerical method for finding approximations to the roots of equations.

It's important to understand that Newton built upon the work of previous mathematicians and scientists. He was a master of synthesizing existing knowledge and applying it to new problems. His contributions laid the foundation for modern science and continue to have a profound impact on our understanding of the universe.