Windowing/virtualization trong React là gì?

Virtualization chỉ render items hiện trong viewport, không render toàn bộ danh sách hàng nghìn items.

• Thư viện: react-window (lightweight), react-virtualized (feature-rich).
• Giảm DOM nodes từ hàng nghìn xuống chỉ ~20-50.
• Cần thiết khi render danh sách lớn (>100 items) gây performance issues.

Virtualization renders only the items currently visible in the viewport instead of the entire list of thousands.

• Libraries: react-window (lightweight) and react-virtualized (feature-rich).
• This reduces DOM nodes from thousands down to roughly 20-50 at any moment.
• It is essential when rendering large lists (100+ items) that cause noticeable performance issues.