Definition: The word "MS" stands for Microsoft, not "ms.js". MS stands for Microsoft Scripting Server, a scripting language used to create custom scripts that interact with the web. The term "MS.js" refers to JavaScript that runs in Microsoft Edge (formerly known as Microsoft Internet Explorer) or Google Chrome browser extensions. This term is commonly used to refer to modern web technologies that allow developers to run applications and websites using JavaScript instead of HTML, CSS, or other markup language.