What Is the Web?

The World Wide Web is a collection of electronic documents that are linked together like a spider web.
[World Wide Web]
These documents are stored on computers called servers located around the world. 
The Web has evolved into a global electronic publishing medium and increasingly, a medium for conducting electronic commerce.

  What Is the Web Made of?

The Web consists of:  [World Wide Web Infrastructure]
Your personal computer 
Web browser software to access the Web 
A connection to an Internet service provider (ISP) 
Servers to host the data  
Routers and switches to direct the flow of data

  How the Web Works

* Web pages are stored on web servers located around the globe.  [World Wide Web Infrastructure]
* Entering the (Uniform Resource Locator) URL of a web page in your web browser or clicking a link sends a request to the server which hosts the page. 
* The server sends the web page to your computer and your web browser displays it on your screen.

  Web Pages

* A web page (such as the one you are looking at now) is an electronic document written in a computer language called HTML (Hypertext Markup Language).  [Web Page]
* Web pages can contain text, graphics, video, animation, and sound, as well as interactive features, such as data entry forms. 
* Each page has a unique address known as a URL (Uniform Resource Locator), which identifies its location on the server. 
* Web pages usually contain hyperlinks to other web pages. Hyperlinks are text and images that reference the URLs of other web pages.


* A website is one or more web pages that relate to a common theme, such as a person, business, organization, or a subject, such as sports.  [Website structure]
* The first page is called the home page, which acts like an index, indicating the content on the site. 
* From the home page, you can click hyperlinks to access other web pages.

  Navigating the Web

There are three main ways to move between web pages or websites: 

Surfing the Net

* Clicking a text hyperlink.
* Clicking a hyperlinked graphic image, such as a button, photograph, or drawing.
* Typing the URL of a web page in the location box (also known as the address field) of your web browser and the pressing the Enter or Return key.

  Identifying a Hyperlink

* Text links are usually underlined and in a different color from the rest of the text.
* To determine if a graphic is hyperlinked, move your cursor arrow over the image. You know the item is hyperlinked if: 
1. The arrow cursor turns into a hand. [Hand Icon]
2. A URL appears in the status bar at the lower left of your web browser.

[Status Bar]


  How Hyperlinks Work

* A text or graphic hyperlink hides a URL.
* Clicking a hyperlink passes the URL to your browser. 

Hyperlinks Image Map

* Clicking different parts of a linked graphic, called an image map, takes you to different web pages or different places on the same page.
* In addition to pointing to web pages, hyperlinks can access media files, such as sound or video clips.

  Using Web URLs

* A URL indicates where the web page is stored on the Internet.
URLs almost never use back slashes (\). All slashes are forward slashes (/).
* You need to type a URL exactly for your browser to locate the desired web page.
* Although URLs may contain spaces between characters, they usually do not.
* Some large websites have multiple URLs that access the same site.
* The location box or address field on your browser indicates the URL of the page you arrived at after clicking a link. 

[Location Box]


  Examples of URLs

* ftp://rtfm.mit.edu/pub/ A directory of files at the Massachusetts Institute of Technology (MIT) that you can download [Examples of Internet Resources]
* http://www.learnthenet.com The home page for the Learn the Net website
* news:rec.gardens.roses A newsgroup about rose gardening

  Web Browsers

A web browser is a software program used to access the World Wide Web. [Web Browsers]
A browser (also known as client software) retrieves data from remote web servers and displays a web page.
The most popular browser comes from Microsoft.
Browsers basically work the same way. Once you know one, you can easily learn the other.

  Anatomy of a Web Browser: The Toolbar

The most useful buttons on your browser toolbar include: [Toolbar Buttons]
Back -- Returns you to the previous page.
Forward -- Returns you to a page you have backed up from.
Home -- Takes you to a home page specified in the browser preferences.
Reload or Refresh -- Downloads the web page from the server again.
Stop -- Stops the browser from loading the current page.
Print -- Lets you make a hard copy of the current document or frame loaded in your browser.

  Saving an Image from the Web

Move your cursor over the graphic. Saving an Image
Windows users: Click the right mouse button. A pop-up box appears.
Save the image to your hard drive by selecting a Save option.
You can accept the current file name or rename the file. (Graphic files are usually in .gif or .jpg format.)

  Printing a Web Page

Most browsers have a Print button on the toolbar that lets you print a web page.  
Some web pages are divided into multiple sections called frames. You can only print one frame at a time. 
To print a particular frame, first select it by clicking it. 
* Then click the Print button or select Print Frame from the File menu.

  Multimedia on the Web

Sound, video, animation, and 3D interactive video are referred to as multimedia. Multimedia
Some multimedia, called streaming media, plays as soon as you access a web page.
Others require that you download the multimedia file to your computer first.
Multimedia files often requires that your browser use a plug-in program.


Plug-ins are small software programs that extend the capabilities of your browser by enabling it to play sounds and video clips or do other functions, such as automatically decompressing files that you download. Plug-Ins
Plug-ins may come with your browser software or can be downloaded from websites.
Some plug-ins enable streaming audio or video, which lets you hear or view a multimedia file before it has completely downloaded to your computer.