Fermions are the fundamental particles that make up all of the matter in the universe. Fermions are themselves divided into two categories: quarks and leptons.

Fundamental Forces

In classical mechanics, forces are thought of as a push or a pull on an object. But in modern physics, forces are thought of more generally as interactions between particles. Although we experience many different forces in our everyday lives, these can all ultimately be explained by just four fundamental interactions between the particles making up everything around us: the weak force, the strong force, electromagnetism, and gravity. The first three are incorporated into the Standard Model of particle physics, while gravity is explained by Einstein’s theory of General Relativity.