The Internet

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Seldom does technology touch as many average people as the Internet has. Everyone, from your grandmother to your children, seems to be using the Internet for personal and business purposes. This section introduces you to the following:

• New concepts and terms you'll encounter on the Internet

• Security considerations

• Using a Web browser

• Adjusting your browser

Concepts/Terms

Most likely, you've experienced the Internet and the World Wide Web. Even so, there's a lot to learn. The following sections will give you some fundamental understanding of the Internet.

The Difference Between the Internet and the World Wide Web

Understand and distinguish between the Internet and the World Wide Web (WWW).

The Internet and the World Wide Web aren't the same thing, although they are related . Sometimes, you will hear the terms used interchangeablyincorrectly. The Internet is a network that forms a global network by connecting millions of computers. The World Wide Web is a particular portion of the content on the Internet: all the hyperlinked Web pages that you'll find as you navigate the Internet with a Web browser.

The exam requires you to have a good understanding of what the Internet and the World Wide Web are and how they differ .

Some New Terms

Define and understand the terms: HTTP, URL, hyperlink, ISP, FTP.

As you use the Internet, you'll encounter some new terms. The following list gives you some of the basic terms that an Internet user should be aware of:

• HTTP: Hypertext Transfer Protocol The protocol used to connect your computer, via a web server, to the Internet and vice versa. HTTP is the language browsers and servers use to talk to one another.

• URL: Uniform Resource Locator An address that directs your request to the appropriate server and directory.

• Hyperlink A special type of text string that accesses a file or page by simply clicking the link.

• ISP: Internet Service Provider A company that provides access to the Internet, usually for a fee.

• FTP: File Transfer Protocol The protocol used to exchange (a form of downloading) files via the Internet.

Web Address Structure

Understand the make-up and structure of a Web address.

A URL consists of several components , which usually use the following syntax:

 http://www.domainname.topleveldomain[/directory/...][,filename] 

In this sample syntax, domainname represents the name of your domain, which you must purchase and register. If you don't have your own domain, your host server determines the domainname . The topleveldomain component is usually a two- to three-letter combination that groups certain site types. You're probably familiar with a few of them, such as .com for commercial, .gov for government agencies, and .org for organizations.

The directory path is controlled by you and determines where filename , the actual file the user is accessing is storedpretty much the same way you'd store any file.

What's a Web Browser?

Know what a Web browser is and what it is used for.

We've told you what the Internet is, and now it's time to learn just how you access all that information. You'll use what's known as a Web browser , which is simply software that allows you to access and display data on the Internet. Throughout this chapter, we use Microsoft Internet Explorer 6.0. Other popular browsers include Netscape Navigator, Opera, and Mozilla.

What's a Search Engine?

Know what a search engine is and what it is used for.

There's a lot of information out there, and chances are that you'll need help finding it. For that, you can rely on a search engine. A search engine is software that runs a keyword or phrase search on Internet documents and returns a list of links that you can use to quickly access possible target documents.

Your Cache and Cookies

Understand the terms cookie, cache.

Sometimes, a Web site customizes what you see, just for you. To complete this customization, the site might save a small text file known as a cookie on your local system. Every time you access the site, information in the cookie is automatically sent to the site to customize what you see.

To speed up your Internet experience, most browsers maintain a cache of files on your local hard drive. For example, the Microsoft logo very rarely changes, so your browser saves a copy the first time that you visit the Microsoft Web site. The next time you go back to the site, your browser uses the saved copy instead of wasting time downloading the logo again.

Security Considerations

Whether you're dealing with a lone system in your home or a corporate intranet, security is a problem you should take seriously.

Protecting a Web Site

Know what a protected Web site is (use of username and password).

One way Web developers protect their sites is to limit visitors and limit what visitors can access. For instance, you've probably been asked to provide a username and password before entering a site: that's one way a developer can protect confidential data. If you don't have the proper credentials, you simply can't get in. Once in, a visitor might also be limited to the data he or she can view.

Digital Certificates

Know what a digital certificate is.

When dealing with online contacts, it's hard to verify that a person is the person she claims to be. When verification is important, you can purchase a digital certificate from a third-party company.

The digital certificate allows you to send an encrypted (coded) message that also contains a key that allows the recipient to decrypt the message.

Web sites also use digital certificates to prove their identities. When you access a Web site with an address that begins with https (instead of the regular http ), your browser checks a digital certificate owned by the Web site. If the certificate is valid, most browsers display a little lock icon at the bottom of the screen to indicate that the site is secure. Avoid giving personal and credit information to unsecured sites.

Encryption

Know what encryption is and why it is used.

An effective means of security is encryption. This process translates the message into code that can only be decrypted by providing a key or password. Encryption prevents eavesdroppers from reading and understanding your messages.

Avoiding Virus Infection

Be aware of the danger of infecting the computer with a virus from a downloaded file.

A virus is a file that replicates itself and it is dangerous, so you should take measures to protect your system. These files are passed via email, infested Web sites, and even by infected files on an external diskette.

The best way to protect your system and subsequently your work is to purchase and install virus-scanning software. (Read more about this software in Chapter 3, "Using the Computer and Managing Files.") Not only does such software protect you from infected email messages, but it also catches virus-laden files that you might accidentally download from the Internet.

Credit Card Fraud

Be aware of the possibility of being subject to fraud when using a credit card on the Internet.

Another serious security issue you might face is credit card fraud. We hope that you'll take measures to protect yourself beforehand and never face the actual problem. If you've ever purchased anything over the Internet using a credit card, chances are that credit card information (including the actual number) is still stored on your local system somewhere. A malicious hacker that knows what he's looking for can easily gain access to a vulnerable system while it's connected to the Internet, glean that information, and then use those credit card numbers to make purchases. Of course, doing so is illegal, but that doesn't really help you once the damage is done. The best way to protect yourself from this type of invasive crime is to use a firewall (which you'll learn about in the next section).

What's a Firewall?

Understand the term firewall .

A firewall is hardware or software that prevents unauthorized access to a lone system or a complex network. All incoming and outgoing messages are examined, and only those meeting specific conditions are allowed in or out. Windows XP includes a built-in firewall called the Internet Connection Firewall that you should always enable when you're browsing the Internet; see Windows XP Help for instructions.

First Steps with the Web Browser

If you haven't actually used a Web browser, now's the time to learn. You start by simply opening and closing Web pages and then learn some of the tricks and tools that can make Web browsing easier and more enjoyable.

Opening and Closing Your Web Browser

Open (and close) a Web browsing application.

Your Web browser opens and closes just like any other Windows-based program. There's probably a shortcut icon (read Chapter 3 for more information on shortcut icons) on the Windows Quick Launch toolbar or the desktop. If that's the case, you can double-click that icon to launch your browser. Otherwise, click the Start menu and click the browser item on the Start menu or click All Programs to display all the software on your system. Figure 8.1 shows Internet Explorer, the default Web browser for Windows.

Figure 8.1. The Internet Explorer Web browser.

To close the browser, click the Windows Close button in the application's title bar or choose Close from the File menu.

Changing the Browser's Home Page

Change the Web browser HomePage/Startpage.

Each time you launch your browser, it displays the same Web page, known as the home page . This page is specific to you, and you can change it anytime you like. To do so, choose Options from the Tools menu, and on the General tab, enter the appropriate URL in the Address control in the Home Page section.

Displaying a New Window

Display a Web page in a new window.

When you click a link to display a new page, your browser leaves the current page and displays the new page. You can force the browser to open the new page in a new window by holding down the Shift key while you click the link. As a result, you'll have two (or many) browser windows open displaying different pages. Alternately, you can right-click the link and choose Open in New Window.

Stopping a Download

Stop a Web page from downloading.

Once you access a page, your browser connects the server and begins to download (transfer) the necessary components to correctly display the page. You can stop this process at any time by simply clicking the Stop button on the toolbar.

Refreshing a Web Page

Refresh a Web page.

What you see isn't always the latest and greatest because your browser caches information on your local system and then displays that information when you access a page. Generally, it makes a page load faster.

To make sure you're seeing the most recent version of a page, click the Refresh button on the toolbar. Doing so forces the server to download a fresh copy of the page instead of loading the page from your locally stored files.

Getting Help

Use available Help functions.

Like almost all Windows-based applications, your browser offers a number of help topics. To access these topics, choose Contents and Index from the Help menu to open a traditional Help window where you can run keyword and phrase searches.

Adjust Settings

Windows-based applications are good at determining the environment settings that users like the most, but you're not stuck with those settings. You can adjust your browser to suit you.

Using Built-In Toolbars

Display, hide built-in toolbars.

By default, the browser launches with a menu bar and a toolbar. To display a toolbar that's not currently displayed, choose Toolbars from the View menu and check the appropriate item. Repeat this action, unchecking the item to hide a toolbar.

Hiding Web Images

Display, hide images on a Web page.

Browsing the Internet can be a timely occupation , especially if you're using a dial-up connection instead of one of the speedier Digital Subscriber Line (DSL) or broadband technologies. You can speed things up a bit by not displaying images as you browse. To change this setting, choose Internet Options from the Tools menu and click the Advanced tab. In the Multimedia section, uncheck the Show Pictures item, and click OK.

The browser displays a broken image placeholder where images would normally be if you downloaded them. You can quickly download an image by right-clicking the broken image placeholder and choosing Show Picture from the resulting menu.

Finding Previously Visited URLs

Displaying previously visited URLs using the browser address bar.

Your browser tracks your visits in what's known as the history . That makes it easy for you to find a site that you want to revisit but didn't bookmark.

To access your browser's history, click the History button on the toolbar to open the History panel, as shown in Figure 8.2. This window lists all the sites you've visited in the previous 20 days (including the current day). In addition, the address bar (where you enter the URL) is actually a combo box. Use its drop-down list to show the most recently visited sites.

Figure 8.2. Use the browser's History panel to quickly access pages you've visited before.

Deleting History

Delete browsing history.

Maintaining the historical data takes a bit of hard drive space (albeit not that much). In addition, you might not want anyone else to know the different sites you've hit. To erase the historical data, choose Internet Options from the Tools menu and click the General tab. At the bottom of the resulting dialog box, click the Clear History button (in the History section).

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