Welcome back to “Let’s Master React Hooks Together” — the series where we learn React hooks step by step in the most beginner-friendly way possible.

So far in this series, we’ve already explored hooks like useState and useEffect , and by now you’ve probably started noticing one important thing about React:

React components re-render a lot.

And honestly, that’s completely normal. React is designed that way.

But once applications start growing, re-rendering can sometimes create performance problems — especially when expensive calculations run again and again unnecessarily.

That’s exactly where today’s hook enters the picture:

useMemo ()

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At first glance, useMemo looks confusing.…