Josh W Comeau:

So, I'll be honest. I had been working professionally with React for years without really understanding how React's re-rendering process worked. 😅

I think this is true for lots of React developers. We understand enough to get by, but if you ask a group of React developers a question like “What triggers a re-render in React?”, you'll likely get a handful of different hand-wavy answers.

There are a lot of misconceptions out there about this topic, and it can lead to a lot of uncertainty. If we don't understand React's render cycle, how can we understand how to use React.memo, or when we should wrap our functions in useCallback??

Josh’s post is a good refresher on why React re-renders.