What Is a Web Browser?

A web browser is a program that your computer runs to communicate with web servers on the Internet so that it can download the documents you ask for and display them. At a bare minimum, a web browser has to be able to understand HTML and display text. In recent years , however, Internet users have come to expect a lot more. A state-of-the-art web browser provides a full multimedia experience, complete with pictures, sound, video, active content, and 3-D imaging.

What Are Add-ons?

Add-ons , which are also called plug-ins , are programs that are independent of your web browser but "plug in" to it in a seamless way, so that you might not even be aware that you are using software that is not part of the web browser. Typically, add-ons arise when a software company develops a way to display a new type of data over the Web such as Adobe PDF files or streaming audio. Rather than create a whole new browser with this additional capability, the software company writes a plug-in for popular web browsers like Internet Explorer or Mozilla Firefox. Users who want to extend the capabilities of their browser in this particular way can install the plug-in, which then operates as if it is part of the web browser.

Typically, installing an add-on is fairly painless. Web pages that contain content requiring a special add-on usually include instructions for downloading and installing the plug-in. When you run Internet Explorer with its default security settings, the Information Bar (at the top of the page) displays a warning message that the page needs to install an add-on. You can click the Information Bar and then continue with the installation process. The main inconvenience is the length of time necessary to download the add-on (which is not even that long if you have a broadband Internet connection). Installing the add-on is usually a simple matter of clicking a few buttons and perhaps registering with the company that makes the plug-in.

As with any kind of software, downloading and installing an add-on requires faith in whoever created and distributed it. An add-on can introduce viruses into your system, modify files without your consent , or transmit data from your machine without your knowledge. Add-ons from reputable software companies are as safe as any other kind of Internet software, but you should be cautious about downloading plug-ins from web sites that you know nothing about.

With IE 7, you can manage add-ons using the Tools Manage Add-ons menu option. The Enable Or Disable Add-On command displays the Manage Add-ons dialog box, where you can view installed add-ons, turn on or off installed add-ons, and delete add-ons. The Find More Add-ons command displays the Add-ons For Microsoft Internet Explorer web page, from which you can download add-ons.

What Is the Default Web Browser?

The default web browser is the application that Windows uses to open a web page when you haven't told it what browser to use-for example, when you click a web link in an e-mail message or choose a web page from the Favorites menu. Initially, Internet Explorer is the default web browser under Windows Vista, but you can choose another browser to be the default if you want.

You can, of course, open any web browser you want and use it to browse the web, whether it is the default browser or not. You can even have several browsers running at the same time-for example, Internet Explorer and Mozilla Firefox.

What Is Internet Explorer?

Internet Explorer is Microsoft's web browser. It intentionally resembles Windows Explorer, and it is an integral part of Windows Vista-Windows uses some of the same code for displaying the Control Panel, Help And Support Center, and other pages. Having Internet Explorer doesn't depend on any decisions you might have made during installation, and you couldn't uninstall it if you wanted to, because many other Windows programs use Internet Explorer's code to display HTML-formatted information. You can uninstall or delete the shortcuts to Internet Explorer from your desktop, taskbar, and Start menu, but the program remains installed.

Internet Explorer 7 is the version that comes with Windows Vista. It has some new features compared to previous versions, such as tabs, which we spell out in the remainder of this chapter. Fundamentally, though, if you have used earlier versions of IE, you won't have much trouble figuring out how to use IE 7.