React Hooks are a new addition in React 16.8 that let you use state and other React features without writing a class component. In other words, Hooks are functions that let you “hook into” React state and lifecycle features from function components. (They do not work inside class components.)
React provides a few built-in Hooks like useState. You can also create your own Hooks to reuse stateful behavior between different components.
Source: https://www.smashingmagazine.com/2020/04/react-hooks-best-practices/