React Hooks — Precise Definition
Hooks are functions that let you “hook into” React state and lifecycle features from function components. Hooks don’t work inside classes…
Hooks are functions that let you “hook into” React state and lifecycle features from function components. Hooks don’t work inside classes — they let you use React without classes.
(An extract from official React documentation for hooks. https://reactjs.org/docs/hooks-overview.html)