One of the biggest misconceptions I had early in my career was believing JavaScript itself handled things like: timers network requests DOM events file system operations It turns out… JavaScript engines like V8 don’t actually implement any of those features. Take this example: ```js id="g7q2vn" setTimeout(() => { console.log("Hello"); }, 2000); Most developers assume: > JavaScript starts a timer and waits 2 seconds. But that’s not what happens. --- # What V8 Actually Does V8 only handles: * parsing JavaScript * compiling JavaScript * executing JavaScript That’s it. It has no built-in understanding of: * timers * HTTP requests * mouse clicks * file systems * sockets Those capabilities are provided by the runtime environment around V8. Depending on where your code runs, that runtime could be: * the browser * Node.js * Deno * Bun --- # So who handles `setTimeout()`?…