JavaScript is a programming language designed specifically for electronic documents on the World Wide Web. Documents on the web are written in Hypertext Markup Language (HTML). JavaScript programs are embedded within HTML to add dynamic interactivity to web documents.

JavaScript may look like the programming language Java, but it is not Java. As a scripting language, JavaScript is intended to take web page designers a step beyond HTML without the complexity of a full programming language. A simple JavaScript program can add interesting interactive functions to a web page. JavaScript is also suitable for the development of large and elaborate user interfaces in web documents. Good programming skills are necessary to master it, and sophisticated tools are becoming available for JavaScript development.

JavaScript is not compiled. Embedded within HTML, JavaScript is interpreted by the web browser. A JavaScript program can control document content and...