SSR (Server Side Rendering) ka matlab hai ke HTML server pe generate hoti hai aur browser me send hoti hai. Next.js me layouts & pages by default 'Server Components' hote hain — yeh rendering server par hoti hai, not browser.
Jab interactive UI chahiye (like buttons, input handling, etc.), tab aap 'use client' likh ke Client Components use karte ho. Yeh components sirf browser me run karte hain.
✅ Pro Tip: Next.js allows hybrid rendering. SSR se performance milegi, aur CSR se rich interactivity. Use both strategically!