Every concept in JS connects back to these four pillars. Learn them in order — each one unlocks the next. Skip one and the rest becomes memorization instead of understanding.
JS is single-threaded. The event loop is the engine that handles async operations without blocking — call stack, microtask queue, macrotask queue.
Callbacks → Promises → async/await. The evolution of handling async operations cleanly. Foundation of every API call, fetch, and real-time feature.
The DOM is JS's interface to the browser. Modules are how modern JS is organized. Together they form the foundation of every frontend application.
JS uses prototype-based inheritance. Classes are sugar on top. Understanding the chain explains how React hooks, Vue, and every framework works internally.
The Event Loop explains HOW JS runs. Async Programming uses that engine. The DOM is what you control with async code in the browser. Prototype/OOP is what every framework (React, Vue, Node) is built on top of. Each pillar is the prerequisite for the next. Learn them in sequence — not in isolation.
await doesn't block the thread without knowing the event loop. Every Promise runs through the microtask queue.