The World Wide Web

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The World Wide Web
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The Web

• Accessible to anyone with an Internet connection
• Content of the web
• Text
• Audio
• Video
• Hyperlinks
• Usually blue and underlined
• Clicking on a hyperlink takes you to information
  that is associated with the current web page.
• Multimedia
• Began in 1989

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The Web

• Began in 1989
• Tim Berners-Lee proposed the idea of the web to
  CERN
• 1993
• Web declared open to anyone who would like to use
  it.
• Marc Andreessen introduced Mosaic
• Mosaic is the first graphical web browser
• Later became Netscape.

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How URLs Work

• URL
• Uniform Resource Locator
• The address for a place on the WWW.
• Uses names instead of numbers ex. www.yahoo.com
  and not 192.168.123.120
• User types the address (URL) of a web site into
  the location area in a browser and presses
  return.
• The browser then submits the information to your
  internet service provider (ISP) ie Earthlink or
  AOL

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How URLs Work

• The information reaches a DNS (domain name
  server)
• The DNS translates the URL into a corresponding
  IP address.
• IP stands for Internet Protocol
• IP address is a four part number for a specific
  computer on the internet. Ex. 12.22.118.3
• If there is a corresponding IP then the browser
  is sent the page that has been requested.
• If there is no IP that matches then an error is
  sent to the browser

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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.

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Getting Connected Dial-Up

• Dial-uprequires 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

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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)

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Service Providers

• Def.- 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

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Browsers

• Your window to the Internet.

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Browsers
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.
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Netscape
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Internet Explorer
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.
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Opera
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AOL
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NeoPlanet
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• 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.

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• 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

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Links

• 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.

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Bookmarks

• 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.