CommonJS vs ES Modules

// CommonJS
if (condition) {
  const mod = require('./module');
}

// ES Modules
if (condition) {
  import('./module');
}

Only CommonJS supports dynamic imports
Only ES Modules support dynamic imports
ES Modules support async dynamic imports, CommonJS supports sync dynamic imports
Dynamic imports work differently in each system: 1) CommonJS allows dynamic requires synchronously anywhere in the code, 2) ES Modules support dynamic imports through import() which returns a Promise, 3) CommonJS's require is synchronous and can block the main thread, 4) ES Modules' dynamic import() is always asynchronous and non-blocking, 5) ES Modules' approach better supports code splitting and lazy loading, 6) CommonJS's approach is simpler but can cause performance issues, 7) The asynchronous nature of ES Modules' dynamic imports enables better performance optimization and bundle splitting.
Neither supports dynamic imports