Web browsers have a dedicated JavaScript engine that executes the client code. These engines are also utilized
in some servers and a variety of apps. The most popular runtime system for non-browser usage is Node.js.
JavaScript is a high-level, often just-in-time–compiled language that conforms to the ECMAScript standard.
It has dynamic typing, prototype-based object-orientation, and first-class functions. It is multi-paradigm,
supporting event-driven, functional, and imperative programming styles. It has application programming
interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document
Object Model (DOM).