JavaScript
JavaScript is a scripting language most often used for client-side web development. JavaScript is typically embedded within the HTML of a web page or silently downloaded/called as a separate external file.
Primary among the uses of JavaScript is to interact with the user and the web page in order to manipulate the data or display.
Excellent and common examples of JavaScript usage are:
Despite sharing some common underpinnings, JavaScript is quite unrelated to the language called Java.