Who invented calculus ?

Calculus, as a mathematical discipline, was independently developed by two prominent mathematicians in the late 17th century: Sir Isaac Newton and Gottfried Wilhelm Leibniz.

Isaac Newton (1643–1727):
Newton referred to his method as "the method of fluxions." He developed calculus as a means to describe and solve problems related to motion, forces, and change in physics. His work laid the foundation for classical mechanics. Newton's development of calculus was primarily aimed at addressing the motion of celestial bodies and explaining gravity, as detailed in his seminal work, Philosophiæ Naturalis Principia Mathematica (1687).

Gottfried Wilhelm Leibniz (1646–1716):
Leibniz independently developed calculus around the same time but referred to his method as "differential calculus." He introduced a more systematic notation, including the integral sign (∫) and the "d" used in derivatives (dx, dy). Leibniz's notation proved to be more practical and is the foundation of modern calculus.

There was significant controversy between Newton and Leibniz over who invented calculus first, often referred to as the "calculus priority dispute." Historical records suggest Newton began his work on calculus earlier, but Leibniz published his results first. Today, both are credited with the independent invention of calculus, and their contributions are considered equally vital to its development.