JavaScript is the name of a dynamic language which is based on classless object-oriented (prototype-based) programming. Netscape created JavaScript in 1994, although at first, they called it LiveScript. The script was used in Netscape’s browser, because they needed a language that both professionals and amateurs would take to.
Note that although the new name contains the word “Java” it doesn’t bear any resemblance to the Java programming language. Some features may be similar, in that both languages are object-oriented and the syntax they use looks like the syntax found in the C programming language, but JavaScript has dynamic typing and it’s weakly typed, while Java has static typing. The JavaScript code also contains some functions influenced by the Scheme programming language.
The JavaScript engine or interpreter is the piece of software that allows the script to be executed in applications or web browsers. JavaScript engines are often found in browsers, so there’s no need to enable JavaScript yourself because it’s already enabled. You can change this in the browser itself if you want to.
Chrome lets you enable JavaScript in the Settings menu (look in the Privacy section for Content settings). You can turn it off entirely or just a particular site. In Firefox look in the Tools menu and choose Options. A pop-up window will appear. Click on the Content tab and look for the Enable JavaScript option. In IE the settings are also in the Tools menu. Look for the Internet Options section where you will see the security settings. Select the Custom Level button and then look for Active Scripting in the list.
JavaScript is used almost everywhere, and particularly with web applications. Web companies need JavaScript to add more functions to their sites, and it is very useful for handling interactive features like animations, media playback, data validation, and receiving or sending data to the server without reloading the page. It also makes it easier to track user activity. In addition, JavaScript is versatile enough that it has found its way into various software applications that don’t relate to the web.