portion of browser software that reads and executes javascript
JavaScript engine A JavaScript engine is a program or interpreter which executes JavaScript code. A JavaScript engine may be a traditional interpreter, or it may utilize just-in-time compilation to bytecode in some manner.[1] Although there are several uses for a JavaScript engine, it is most commonly used in Web browsers.[2][3][unreliable source?]
Web page The web page usually means what is visible, but the term may also refer to a computer file, usually written in HTML or a comparable markup language. Web browsers coordinate various web resource elements for the written web page, such as style sheets, scripts, and images, to present the web page. Typical web pages provide hypertext that includes a navigation bar or a sidebar menu linking to other web pages via hyperlinks, often referred to as links.