🚀 React Hooks & Rendering — A Clear Mental Model (For My Future Self Too)

🪝What are React Hooks? Hooks are helpers that let a function component: remember data react to changes 🧠 Core React Hooks (WHAT + WHY) 🔹 useState — data that affects the UI Why it exists: React re-runs components often. Without state, values would reset every time. Use when: The user should see the change. 🔹 useEffect— side work after render Why it exists: Some work should happen after the UI is painted, not during it. Used for: API calls timers 🔹useRef — remember without re-render Why it exists: Sometimes React needs to remember something without updating the UI. Two main uses: DOM access → focus input, scroll, measure Silent storage → timer IDs, previous values, flags 🔹 useContext — shared/global data Why it exists: To avoid passing props through many layers. Used for: logged-in user theme 🔹 useMemo — avoid heavy recalculations Why it exists: React re-runs components often → slow calculations can repeat unnecessarily. Use when: calculation is expensive 🔹 useCallback — stable functions Why it exists: Functions are recreated on every render. Used mainly when: passing callbacks to optimized child components 🌍 Rendering Types (WHY they exist) 🔹 CSR — Client Side Rendering What: Browser builds the UI Best for: dashboards, internal tools 🔹 SSR — Server Side Rendering What: Server sends ready HTML Why: Search engines need content 🔹 SSG — Static Site Generation What: Page built once at build time Why: Some content rarely changes Hope it helps someone else too