JavaScript is commonly referred to as an interpreted language, primarily because its code is executed directly by the JavaScript engine within web browsers or server-side environments like Node.js without an explicit compilation step. This means that JavaScript source code is typically interpreted line by line during execution. However, the distinction between interpreted and compiled languages has blurred in recent years. Modern JavaScript engines, such as V8 in Chrome and SpiderMonkey in Firefox, employ sophisticated Just-In-Time (JIT) compilation techniques. These engines can dynamically analyze and optimize JavaScript code during runtime, translating parts of it into optimized machine code for better performance. Additionally, tools like TypeScript or Babel can transpile modern JavaScript syntax into older versions or optimize code ahead of time. Some JavaScript engines also generate bytecode or intermediate representations of the code before execution, further complicating the distinction between interpretation and compilation. Therefore, while JavaScript is often categorized as interpreted due to its execution model, it incorporates elements of both interpreted and compiled languages in practice.