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4.5 ROLE OF JAVASCRIPT IN WEB DEVELOPMENT
HTML Language is used to create web documents or web pages. JavaScript is embedded in the HTML code. The
<script> tag informs the browser about JavaScript code in the HTML code. A complete web page can be visualized as
three separate layers which allows the designer to concentrate on a particular part and programmer can work on the
code in JavaScript application. Here is a brief description of these layers.
Structure
This is the part of the website that users see, and it consists of text, images, and links that allow the user to navigate
through the various pages or the entire website. HTML tags are used to specify the document’s structure. The browser
perceives the display as a tree-like structure.
Style
This layer describes the appearance of the document. Setting the font colour, background image, border, and alignment,
for example, all fall under this layer. These operations can be carried out utilising the page’s HTML elements or the
cascading style sheets (CSS). When we have to make modifications in multiple places on a page or pages, the former is
more difficult, whereas the same CSS can be used on thousands of pages.
Behaviour
This layer outlines the actions that the page can execute. A user can interact with a web page by pressing specific keys,
rolling or clicking the mouse, filling out forms, and so on. JavaScript makes it simple by processing events that occur on
the web page and displaying the appropriate answer.
4.6 WEB BROWSER
A browser is an application program that has a graphical user interface for displaying HTML files. It is used to browse
the World Wide Web and gives users a method to view and interact with all of the information there. Firefox and
Microsoft Edge are the two most widely used browsers. Apple Safari, Google Chrome, and Opera are some of the other
popular browsers. JavaScript is incorporated into the browsing environment and has the ability to access and modify
information about the browser and HTML sites, modifying how things are shown on your screen.
Setting JavaScript in Internet Explorer
Follow the given steps to turn on or turn off JavaScript in Internet Explorer:
Step 1: Click on the Tools icon. A drop-down menu appears.
Step 2: Select the Internet Options from the drop-down menu. The Internet Options dialog box appears.
Introduction to Dynamic Websites Using JavaScript 281

