SMU MBA ASSIGNMENTS

Browser components

Now let us learn the architecture of a Web browser with the help of reference architecture. This reference architecture is the basic architecture for Web browsers and helps you to easily understand the various components that exist in the Web browser.

 

 

Figure 1.1: Main Components of Browser^[1]

As shown in the figure 1.1 the Web browser consists of seven main components, each having a specific task to perform and they are:

· User interface: It consists of an address bar where you can enter the URL, bookmark menu to save the links of your favourite Web pages, back/forward button to navigate to the previous Web page/next Web page, and so on.

· Browser engine: It is the interface through which you can ask questions to the browser and manipulate the rendering engine. It also sets the layout of a Web page formatted with HTML tags within a browser.

· Rendering engine: It is displays the content you had requested, after obtaining it from the respective Web server.

· Networking: It is used for calling the network for example, raising an HTTP request for a URL connection through the server.

· Display backend: It provides drawing tools, user interface widgets, and fonts that help to display text and graphics.

· Javascript interpreter: It is used to parse and execute the codes of written using the Java script (refer Unit 6).

· Data storage: This enables the browser to save all the data on the hard disk and acts as the database of the browser.

Features of browser

Now that we have learnt about the components of a browser, let us now study some of the most important features of a browser. The figure 1.2 shows the screen shot of the Microsoft’s Internet Explorer Web browser. The arrows point to the features that are available on the Web browser along with the name of the corresponding feature mentioned at the other end of the arrow.

 

Figure 1.2: Web Browser and its Features

From the figure 1.2 you can see some of the features that are present as icons or buttons on a Web browser. If you do not find it as a button you can find the same in one of the menus provided in the menu bar. Let us now briefly discuss the features that are mentioned in the figure 1.2:

· Address field: This is the area on the browser window where you enter the Web page address or URL. At the right end of this area, there is a small arrow pointing towards the menu bar, when you click this arrow you will view a list of some of the Websites that you have visited recently. When you click on these URLs you will view the respective Website or else you can directly enter the address in the address field. After you enter the address you can either press “Enter” or click on the “Go” button (which is present next to the downward facing arrow button in some browsers).

· Back and forward buttons: The back button is used to go back to the previous page that you have opened in a particular browser window. The forward button allows you to view pages that you have previously viewed in that browser window. In some browsers, there is a small arrow pointing towards the menu bar arrow right next to these buttons, when you click this arrow you will see the list of Websites that you have visited after opening the browser window.

· Home button: When you click this button you will be able to view the page that you have set as home page. A home page is a default page that opens when you open the browser window.

· Menu bar: A menu bar is a part of each browser window, it contains menus like File, Edit, View, Favourites or Bookmarks, Tools and Help.

· Refresh or reload: When you click the refresh or reload button, the page is updated. For example, if you think that the contents of a browser window may have changed since the last time you viewed it, you can click this button to update the page.

· Security indicators: At the left corner of the window, a lock icon appears when you use a browser and this is called padlock. If the padlock is in a lock position then you can say that your server connection is secure, i.e. the data being sent and received by the server is encrypted. This indicates that nobody else can access this data. There is another way to find out whether your browser is secure or not and that is done by looking at the URL. If the URL of your Website begins with “https://” for example, you enter an address “www.gofind.com” in the address field and press enter or click “Go” then automatically the address changes to “https://www.gofind.com” indicating that your browser connection is secure.

· Status bar: This is a bar at the bottom of the browser window which indicates the URL of the Web page currently being loaded into the browser window. It also displays the URL of the link on which the cursor of your mouse is placed. While loading, the Web page shows a progress indicator which shows how much percentage of a file has been downloaded.

· Stop button: This button is used to stop the browser from loading the Web page on to the browsing window.