Internet Computer Fundamentals
The World Wide Web
By now, Web browsers have been used by a large percentage of the civilized world. People use a Web browser every time they use the Web. People use one to do their online shopping, check their stocks, bank account, or whatever else Web page authors have dreamed up.
The strange thing is, many of these people still don't realize that what they are using is a Web browser. To them, it is just "the Internet". Ask which Web browser they use, and you will get a confused "huh?" as a response. By the end of this lecture, you should be able to help clear up the confusion for them.
In the simplest of terms, when you use the WWW, you are "browsing" it. Therefore, logically, the thing that you would use to "browse" the Web, would be a "browser". Hence the name. But what is it, exactly?
What Is a Browser?
A Web browser is the client part of the WWW client/server model. It is also referred to as a Web client. In the most technical of terms, it is referred to as a user agent. There are many different flavours of browsers on the market today, but they all have the most basic thing in common: they are used to view Web (HTML) pages.
Today's browser is usually capable of much more than that though. It can store "bookmarks" of your favourite pages. It can be used to download files. It can be used to launch other programs to access other non-Web Internet resources (like email). In the case of Microsoft's Internet Explorer, it can even browse your own computer.
History of Web Browsers
The first Web browser was actually a browser/editor. It could view Web pages as well as create them. This Web browser was written by the same man who created the World Wide Web: Tim Berners Lee. Its name, appropriately enough, was "WorldWideWeb". It was renamed Nexus at a later date to avoid confusion.
The WWW was made available for download in 1991. Also in 1991, a line-mode browser was released that would work on UNIX computers, and even MS-DOS. Line-mode browsers are text only, so there was no GUI, or graphics. Commands had to be typed in. In 1993, a line-mode Web browser called "Lynx" was released. Lynx is the only of these early browsers that is still being used today. Anyone using a computer with no GUI can use Lynx to view Web pages. Lynx is also popular with people who have vision impairment, as Lynx can be combined with a "screen reader" that will present the Web page in an audio format.
In the following years, a few more browsers were release by other organizations. A few of these early browsers had names like Erwise and Viola, but there were no GUI browsers that could be used on Windows or Mac.
In 1993, NCSA Mosaic was released for both Windows and Macintosh computers. Now the average user had an easy to use, graphical browser to use the Web.
In 1994, the creators of Mosaic left NCSA and formed a company called "Mosaic Communications Corp", which was later changed to "Netscape". They released their first browser, Netscape in 1994. By 1995, Netscape had an estimated 80% of the market share. Then along came Microsoft.
Microsoft began to realize that the Web was going to be big, and decided to get into the game. They released Internet Explorer in August 1995 with Windows 95. It was behind Netscape, and Microsoft had to play "catch up" to Netscape. However, Microsoft had a major advantage. Internet Explorer was distributed for free. Netscape eventually had to offer its own browser for free in order to compete.
This period of competition between browsers is commonly referred to as the "Browser Wars" with Internet Explorer (IE) and Netscape releasing new versions several times a year, and users eager to try beta versions of browsers.
By the time both browsers had reached the 4.0 version, Microsoft had caught up to Netscape technologically and in popularity. At the end of 2001, both browsers were at 6.0 versions. Microsoft, however, now has the vast market share. In the spring of 2002, it is estimated that IE has well over 80% of the market share. Even many Mac users, who for a long time favoured Netscape, now prefer the Macintosh version of IE over Netscape.
These days, there are other browsers available that work very well. Browsers such as the open source Mozilla, or Opera are nice alternatives to IE and Netscape.
Different Web Browsers
Internet Explorer (IE), with its integration into Windows, is very easy to use. IE is very quick to load, and it has some nice integrated features like active desktop, which allows you to have a Web page as your Windows desktop. IE has greater security than ever before; Microsoft is constantly releasing security fixes for IE.
IE includes Active X, which allows certain applications to be run from your browser. Active X is very complicated, but one thing that it does is make installing plug-ins much simpler. In Netscape, you have to download and install a plug-in (more on plug-ins later). In IE, you simply have to say "yes" to a dialog box asking you if you want to install and run a certain plug in.
IE also has some great security features that, for instance, allow you to put certain Web sites into a "restricted" zone, and others into a "trusted"zone. It also has six levels of "privacy" that allow you to control how IE handles cookies. (More on cookies later.)
Web developers like IE because of its adherence to WC3 HTML standards as well.
Netscape Navigator should not be confused with Netscape Communicator. Netscape Communicator is a set of applications that includes Netscape Navigator. Communicator includes an email client, a Web page composer, and a few other applications.
Once the world's most popular browser, Netscape Navigator suffered some losses in the "browser wars" it didn't help that Netscape didn't keep up with Microsoft at one point, and stayed with the same 4.x version for a long time. To make matters worse, when Netscape finally released the long anticipated Netscape 6 browser, it was full of bugs and unstable. Netscape fixed a lot of the bugs though, and produced an updated browser, Netscape 6.2.
Netscape 6 and 7 are much more compliant with Web standards than previous versions. Web designers have a much easier time designing pages that will work in both IE 6 and Netscape 7.
As well as an assortment of security features, Netscape 6/7 has other unique features such as a link to a handy translator that will translate the page you are looking at into other languages. They are based on the Mozilla project.
Mozilla is an open-source browser project. That means that anyone who knows how to program can volunteer to help build the software. Instead of having a team of a hundred people working on a project, you can now literally have thousands and thousands of people writing, testing, and fixing software from all over the world. One of the off-shoots of the Mozilla project is a browser called Firebird.
Opera was first designed as a small, fast browser that would work well on less powerful computers. It became a popular "alternative" to the two major browsers, IE and Netscape.
One big difference between Opera and the other 2 browsers, is that IE and Netscape were both based on NCSA Mosaic, whereas Opera was written from scratch. Besides this difference, Opera still provides the same functionality of the other browsers, but in a smaller program. Opera runs faster, and takes up less space on your hard drive. (4.6 Megabytes compared to 38.3 for Netscape 6.) Opera is also available for a wider selection of OS's than the other two.
The ad-supported version of Opera is free, or you can purchase the ad-free version for a small sum.
Opera also comes with some unique features that will be discussed later.
Using a Web Browser
Although the above three browsers are different in many ways, they all have the same basic functions. We will get into the difference a bit later. For now, let's talk about basic Web browsing.
The first thing you will probably want to do (after opening the browser) is to see a Web page. The Web browsers will usually be showing its default start page (the page that it starts with). To go to another location, all you do is type that page's URL into the Address bar. Don't worry about the protocol (http://), most browsers will add this in for you. Just type in a fully qualified domain name; such as www.yahoo.com. After you press "Enter", the Web browser will go to that site, and get the default page on its root folder. (Commonly called "index.html".)
Web browsers will all have the same basic buttons. These are: Back, Forward, Stop, Refresh and Home.
The Back button takes you to the previously viewed page. It is usually better to use this button than to use a "back" link in a Web page. The "back" link can get confusing. Even though it appears that you are going "back", to the browser, you are looking at a another new page. So instead of going "back", you are actually going further away from where you were. Always use the browser's Back button.
Most modern browsers will also have some kind of down arrow beside the Back button that will allow you to select from a list of your previously visited Web pages. This feature can be useful because some sites will prevent you from using the back button. In this case, you can use the drop down list, and manually select the previously viewed page you want to go to. (see image).
The Forward button works exactly like the Back button, but goes in the opposite direction. This button will not be available if you haven't used the Back button. Once you have used the Back button, the Forward button allows you to go forward again to where you were. Like the Back button, the Forward button will give you the option of choosing from a list of "forward" sites. (If you have gone "back" far enough.)
The Stop button stops the current page from loading. This can be useful if you have typed in the wrong URL for a page in the address bar, and you don't want to wait for that site to load before typing in the correct address.
The Refresh button sends a request to the Web server to fetch the current page showing on the screen, and display it again. This feature is great for Web designers who are making changes to the document, and who need to see the changes displayed.
Sometimes a browser will show you an older, stored (cached) version of a page. Hitting the Refresh button causes the browser to instead go and get the newest version from the server.
The Home button takes you to whatever your "home page" is defined as. This is the page that the browser displays when you first start it up. (You will learn how to set the home page a bit later.)
These shortcuts will work in all of the three browsers discussed above, except where otherwise noted.
- Go back to previous page - Alt + Left Arrow
- Go forward - Alt + Right Arrow
- Stop loading current page - Esc
- Refresh current page - F5
- Go to Home page - Alt + Home (except Opera)
Web Browsers Summary
- A Web browser is a Web client, and is often referred to as a user agent.
- The first Web browser was created by Tim Berners Lee. It was called WorldWideWeb.
- Line-mode browsers are text-only.
- Lynx is a popular line-mode browser.
- NCSA Mosaic was the first graphical browser available for the home user.
- The creators of Mosaic formed a company called Netscape Communications.
- Netscape was first released in 1994.
- At one point in the mid 1990's, Netscape had 80% of the market share of Web browsers.
- "Browser Wars" is the name given to the heavy competition between Netscape and Microsoft during the mid to late 1990's.
- Internet Explorer is now the world's most popular browser.
- Most of the major browsers have the same basic functions.
- To go to a particular page, type in its URL into the "Address" bar.
- The Back button takes you to the previously viewed Web page.
- The Forward button is only available after you have used Back. It lets you go forward again after using the Back button.
- The Stop button stops a page from loading.
- The Refresh button re-loads the current page from the server.
- The Home button takes you to whatever your "home page" is defined as.
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