Data Fetching in React — Why use React Query?

A practical introduction to data fetching in React. We started with the obvious "just use useEffect" approach, then walked through the pile of complexity it actually buys: race conditions, loading and error states, empty states, manual caching. Then we introduced React Query, which collapses most of that into a single hook — and surveyed its key features: automatic caching, query invalidation, retries, background refetching, pagination + infinite scroll, optimistic updates, polling, prefetching, window-focus refetching, and dependent queries. Live demos compared a manual fetcher to the React Query equivalent, side by side.