Web development is the work involved in developing a Web site for the Internet or an intranet. Web development can range from developing a simple single static page of plain text to complex web applications, electronic businesses, and social network services. A more comprehensive list of tasks to which Web development commonly refers, may include Web engineering, Web design, Web content development, client liaison, client-side/server-side scripting, Web server and network security configuration, and e-commerce development. Every Web Developer must have a basic understanding of HTML, CSS, and JavaScript. Responsive Web Design is used in all types of modern web development. ECMAScript 5 (JavaScript 5) is supported in all modern browsers. Take a good look at it, especially the new array functions.