# React
# Hooks
# useEffect
useEffect will run after the first render. It will also run on every re-render. The second argument we pass it will be its dependencies, the elements that will tell React when and if to re-run the effect or not. That's why, to make the effect run only once, we need to pass an empty array [] as the second argument.
# useMemo and useCallback
They are used to optimize computations to prevent re-renders. Never use them pre-emptively, only use them when needed, as a last resort.
# useLayoutEffect
Only used for DOM measurements. It works like useEffect, but useLayoutEffect is synchronous (render + effect). Read this article for a more detailed explanation.