The World Wide Web

The WebI. Accessible to anyone with an Internet connection

II. Content of the webA. Text B. AudioC. VideoD. Hyperlinks

1. Usually blue and underlined2. Clicking on a hyperlink takes you to information that is

associated with the current web page.

E. Multimedia

III. Began in 1989

The WebIII. Began in 1989

A. Tim Berners-Lee proposed the idea of the web to CERN

IV. 1993 A. Web declared open to anyone who would like to use

it.

B. Marc Andreessen introduced Mosaic™1. Mosaic is the first graphical web browser

2. Later became Netscape.

How URL’s WorkI. URL

A. Uniform Resource LocatorB. The address for a place on the WWW.C. Uses names instead of numbers ex. www.yahoo.com

and not 192.168.123.120

II. User types the address (URL) of a web site into the location area in a browser and presses return.

III. The browser then submits the information to your internet service provider (ISP) ie Earthlink or AOL

How URL’s WorkIV. The information reaches a DNS (domain name server)

V. The DNS translates the URL into a corresponding IP address.A. IP stands for Internet Protocol

B. IP address is a four part number for a specific computer on the internet. Ex. 12.22.118.3

VI. If there is a corresponding IP then the browser is sent the page that has been requested.

VII. If there is no IP that matches then an error is sent to the browser

Getting Connected

• Connection types– Dial up

– Dedicated

• Service Providers– ISPs can be very large corporations or run by a local

business

• Browser– There are many to choose from. Each has strengths and

weaknesses.

Getting Connected: Dial-Up

• Dial-up:requires a modem to connect to the network through telephone lines.

• This requires the data signal to be changed to and from analogue.

• Speeds up to 56kbps

Getting Connected: Dedicated

• Dedicated Connection: directly connected to the network. No need for a phone modem nor telephone company.

• Speeds up to and beyond 1.5 mbps (1500kbps)

Service ProvidersDef.- A service provider is a company that gives

you access to the internet. The money you pay this company allows you to dial-up a connection to the Internet or provides the equipment that you use to connect to the Internet.

• Earthlink• AOL• NetZero

Browsers

Your window to the Internet.

A browser is a program that allows you to view pages on the WWW. It is the program that reads html so that you can view the page. You can think of it as a ‘window’ to the WWW.

Browsers

Netscape

You will find many of the same features here. Instead of bookmarks, you have “Favorites.” There is also a “History” tab that will allow you to see where you have been.

Internet Explorer

Opera

AOL

NeoPlanet

• Back Button-Takes you back to the previous page. If you hold your mouse down on the back button you get a list of all the websites you have visited during the current session.

• Forward Button- The opposite of the back button.

• Home- What ever home page your service provider defaults to. You can change this.

• Location- This is where the address or URL is displayed. You can type an address here.

• Search Button- One way to search, Netscape uses “Excite” as its search engine

• Reload Button-Clicking this causes the page to reload and show any changes. Holding shift and reload tells the browser to skip the cache and get the newest page on the server.

• Menu items:

– File - print, save

– Edit - copy, paste,search option

– View - The way things look

– Go - back, home, all web sites during current session

– Bookmarks - Add a bookmark, see list of bookmarks, edit bookmarks.

– Communicator - This will take you to other parts of the program.

– Help

• When ever you click on something, and the browser takes you somewhere, you have clicked on a link. A link can be a word, a picture, a button, etc. Links can be thought of as connections to associated information.

• Clicking on a link takes you either to another web page on the same web site, or to another web site altogether.

Links

• Bookmarks offer a convenient means to retrieve pages whose locations (URLs) you've saved. You store your bookmarks in a list that's saved on your hard disk. Once you add a bookmark to your list, the item stays until you remove it.

Bookmarks