1. Navigating The World Wide Web
Lesson 1

2. What is the World Wide Web?
Timothy Berners-Lee and other researchers at the CERN nuclear research facility near Geneva, Switzerland laid the foundations for the World Wide Web, or the Web, in 1989
They developed a system of interlinked hypertext documents that allowed their users to easily navigate from one topic to another
The Internet is a global network of computers linked by high-speed data lines and wireless systems
The World Wide Web (Web or WWW for short) is just one of several services provided by the Internet, which consists of a system of interconnected networks
Hypertext is a way to organize information so that you can click links to jump from one piece of information to another

3. How the World Wide Web Works
Hypertext—can read and navigate text in non linear way
Graphical and Easy to Navigate—versus early days of the Internet
Cross-platform
Distributed—information not located in one centralized location
Dynamic Information
Interactive Information

4. Linear versus hypertext documents
When you read a book, you follow a linear progression, reading one page after another
With hypertext, you progress through pages in whatever way is best suited to you and your objectives
Linear versus hypertext documents

5. Web Pages
Each document on the World Wide Web is referred to as a Web page
A Web site is a related collection of Web pages
A home page is the first document users see when they access a Web site

6. Web Servers
Web pages are stored on a Web server, or host, which is a computer that stores and sends (serves) requested Web pages and other files

7. Web Pages and Web Servers

8. Web Browsers
A Web browser retrieves the page from the Web server and renders it on the user’s computer or other device
The earliest browsers, known as text-based browsers, were incapable of displaying images

9. Understanding URLs
To create a link to a resource on the Internet, you need to know its URL
A Uniform Resource Locator (URL) specifies the precise location of a resource on the Internet
A protocol is a set of rules defining how information is exchanged between two resources

10. Understanding URLs
Your Web browser communicates with Web servers using the Hypertext Transfer Protocol (HTTP)
The URLs for all Web pages must start with the scheme “http”
Other Internet resources use different protocols and have different scheme names

11. Common Communication Protocols

12. A sample URL for a Web page
Understanding URLs
A sample URL for a Web page

13. Understanding URLs
If a URL includes no path, then it indicates the topmost folder in the server’s directory/folder tree
If a URL does not specify a filename, the server searches for a file named “index.htm” or “default.htm”

14. End of Presentation