modulepreload optimizes module loading by preloading dependencies: 1) It allows browsers to download and parse modules before they're needed, 2) It can improve performance by parallelizing module downloads, 3) It's particularly useful for critical modules that will be needed soon, 4) It supports loading entire module dependency trees, 5) It can reduce application startup time by pre-parsing modules, 6) It's different from regular preload as it handles the entire module graph, 7) It's an important optimization technique for module-based applications.