JavaScript (commonly abbreviated JS) is an interpreted programming language, a dialect of the ECMAScript standard. It is defined as object oriented, based on prototypes, imperative, weakly typed and dynamic.
It is mainly used in its client-side form, implemented as part of a web browser allowing improvements in the user interface and dynamic web pages although there is a form of server-side JavaScript (Server- Side JavaScript or SSJS). Its use in external applications to the web, for example in PDF documents, desktop applications (mostly widgets) is also significant.
Since 2012, all modern browsers fully support ECMAScript 5.1, a javascript version. The older browsers support at least ECMAScript 3. The sixth edition was released in July 2015.
JavaScript was designed with a C-like syntax, although it adopts names and conventions of the Java programming language. However, Java and JavaScript have different semantics and purposes.
All modern browsers interpret embedded JavaScript code in web pages. To interact with a web page, the JavaScript language of a Document Object Model (DOM) implementation is provided.
Traditionally it was used in HTML web pages to perform operations and only in the framework of the client application, without access to server functions. It is currently widely used to send and receive information from the server along with help from other technologies such as AJAX. JavaScript is interpreted in the user agent at the same time that the sentences are downloaded along with the HTML code.
Since the release of the ECMAScript 1 standard in June 1997, there have been versions 2, 3 and 5, which is the most used today (4 was abandoned). The ECMAScript 6 version was closed and published in June 2015. 