React Performance Optimization: Code Splitting

Dynamic import() is the JavaScript feature that makes code splitting possible in modern web applications. Unlike static imports (import statements at the top of files), dynamic import() is a function that returns a Promise which resolves to the imported module. This allows JavaScript bundlers like webpack to automatically split your code at these import points. When React.lazy uses dynamic import(), it leverages this feature to create code-split chunks that are only loaded when needed.