Simple way to integrate form checks, animations and other features into a website. Disadvantage: If a user has deactivated Java-Script in his browser, these features are not displayed.
JavaScript is a scripting language developed by Netscape in 1995 to extend the capabilities of HTML and CSS. Despite the name similarity JavaScript has only few similarities with the programming language Java. JavaScript was first mainly used on the client side. Meanwhile, there are also some server-side application such as the framework Node.js and the JScript .NET in an ASP or ASP.NET environment on Microsoft Internet Information Services. A script is executed by the browser in the form of a single thread, in a so-called sandbox. This is to prevent access to the file system.
There are now various libraries (collection of functions) and frameworks (structure of programming) for creating websites. The best known are: Dojo Toolkit, Angular, jQuery, Ext JS, MooTools, Prototype, Qooxdoo, React, Vue.js.