ArrayBuffer, TypedArrays & Binary Data Arrays & Array Methods Async Iterators & Streams Browser Storage & Web APIs Classes & Class Syntax Date, Time & Internationalization (Intl API) Debugging, Testing & Tooling Design Patterns in JavaScript Destructuring, Spread & Rest DOM & Events Error Handling ES Modules Event Loop & Concurrency Functional Programming Iterators & Generators JSON & Data Serialization Map, Set, WeakMap & WeakSet Memory Management & Garbage Collection Networking: Fetch, XHR, WebSockets & CORS Numbers, Math & BigInt Objects, Property Descriptors & Immutability Optional Chaining & Nullish Coalescing Package Management, Bundlers & Transpilation (npm, Webpack/Vite, Babel) Performance Optimization: Debouncing, Throttling & Memoization Promises & async/await Prototypes & Inheritance Proxy & Reflect Regular Expressions Scope, Hoisting & Closures Security: XSS, CSRF & Content Security Policy Service Workers & Progressive Web Apps Strings & Template Literals Symbols & Well-Known Symbols this & Binding Types & Coercion Web Components & Custom Elements Web Workers & Multithreading