Transcript 2 - Dr. Abdullah Almutairi | Kuwait University

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Introduction to Internet, WWW,
and Web browsers
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Internet and World
Wide Web
Internet and World Wide Web
(WWW)
What is Internet?
 Internet is a short form of the technical term internetwork.
 Internet is composed of collection of networks connecting millions
of computers together.
 Internet consists of hardware and software infrastructure that enables
computers to communicate and exchange information.
 Internet is not controlled or owned by a single authority or
organization.
– Different organizations, companies, governments, universities, and service
providers control different parts of the Internet by managing their own networks.
 A number of organizations maintains and sets the policies and protocols
that defines how the Internet is used. Some of these organizations are
– Internet Corporation for Assigned Names and Numbers (ICANN)
– Internet Engineering Task Force (IETF)
– National Science Foundation (NFS)
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Internet
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Internet
 Many different services runs on the Internet
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World Wide Web
Email
Instant messaging services (MSN Live, yahoo messengers)
File sharing and transfer services (FTP, bittorrent)
 Internet and the WWW are not the same.
– WWW is a services that is built on top of the Internet.
– The Web is just one way to exchange information on the Internet.
 The Internet Protocol Suite (TCP/IP) provides the ability
for the machines and networks to communicate.
– Enables the different services to exchange information.
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World Wide Web (WWW)
 What is WWW or Web?
– An information sharing model that provides the means for sharing and
accessing, of information on the internet (information system).
 The Web
– Consists of hypertext documents (web pages) that can contain text, images,
videos, and hyperlinks which allows navigation between the documents.
– Uses Hyper Text Transfer Protocol (HTTP) to exchange information.
 Web pages are created using markup languages HTML or
XHML.
– Today, complex web sites utilize a set of different technologies to create its
web pages like HTML or XHTML, CSS, javascripts, PHP, perl, ASP.NET,
jsp, …
 Users access web pages using clients called “Web browsers”
(IE, Firefox, Chrome, Safari, Opera).
History of the Internet and World
Wide Web
 The Internet began as project in the late 1960’s by
ARPA (Advanced Research Projects Agency of DOD)
to create a communications network.
 In the 1969 ARPAnet was created, connecting four
western universities.
 Later new connections were soon added to the
network, bringing the number of machines up to 23
in 1971, 111 in 1977.
 In 2012, it is estimated that 8.7 Billion devices are
connected to the internet.
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History of the Internet and World
Wide Web
 ARPA’s goals
– Allow multiple users to send and receive info at same time
– Network operated packet switching technique
- Digital data sent in small packages called packets
- Packets contained data, address info, error-control info and
sequencing info
- Greatly reduced transmission costs of dedicated
communications lines
– Network designed to be operated without centralized
control
- If portion of network fails, remaining portions still able to
route packets
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History of the Internet and World
Wide Web
 Transmission Control Protocol (TCP)
– Name of protocols for communicating over ARPAnet.
– Ensured that messages were properly routed and that they
arrived intact.
 Organizations implemented own networks
– Used both for intra-organization and communication.
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History of the Internet and World
Wide Web
 Huge variety of networking hardware and software appeared
– ARPA achieved inter-communication between all platforms
with development of the IP
- Internetworking Protocol
- Current architecture of Internet
– Combined set of protocols called TCP/IP
 The Internet
– Limited to universities and research institutions
– Military became big user
– Next, government decided to access Internet for
commercial purposes
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History of the Internet and World
Wide Web
 Internet traffic grew
– Businesses spent heavily to improve Internet
- Better service their clients
– In 1989, Tim Berners-Lee invents Hyper Text Markup
Language (HTML)
- Also writes communication protocols to form the backbone new
information system = World Wide Web
- Hypertext Transfer Protocol (HTTP)—a communications protocol
used to send information over the web
– Web use exploded with availability in 1993 of the Mosaic
browser
– Marc Andreessen founds Netscape
- Company many credit with initiating the explosive Internet of late
1990s.
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World Wide Web Consortium (W3C)
 W3C Founded in 1994 by Tim Berners-Lee
 Homepage at www.w3.org
 Goals
– Internet universally accessible
– Standardization
 W3C Recommendations:
– Technologies standardized by W3C include
- XHTML, CSS, HTML (now considered a “legacy”
technology), and XML.
- Not an actual software product, but a document that specifies
a technology’s role, syntax rules and so forth.
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Web 2.0
 2003 noticeable shift in how people and businesses were using the web
and developing web-based applications
 The term Web 2.0 was coined by Dale Dougherty of O’Reilly
– Web 2.0 definition = companies use the web as a platform to create
collaborative, community-based sites (e.g., social networking sites, blogs,
wikis, etc.).
– Web 2.0 is focused on the ability for people to collaborate, share
information , and create Web-based communities.
– Web 2.0 is dynamic.
 Web 1.0 (1990s and early 2000s) focused on a small number of
companies and advertisers producing content for users to access.
– contains static HTML pages.
 Websites like MySpace , Facebook , Flickr , YouTube, eBay and
Wikipedia , users create the content, companies provide the platforms.
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Web Browser
Basics: Internet
Explorer and
Firefox
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Introduction to the Internet Explorer 7
and Firefox 2 Web Browsers
 Web browsers
– Software programs that access web’s rich content
– www portion of the Internet
- hyperlinked documents written in HTML & XHTML and rich media
 Popular web browsers
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Microsoft’s Internet Explorer (IE)
Mozilla’s Firefox (FF)
Apple’s Safari
Opera Software’s Opera
Google’s Chrome
Examples in the book are for both IE7 and FF2
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Connecting to the Internet
 Computer + web browser software + ISP =
Internet access
– Computer must have modem or network card
- Modem - hardware that converts data to audio tones and transmits
the data over phone lines
- Network card or network interface card (NIC) - hardware that allows
a computer to connect to the Internet through a network or a highspeed Internet connection.
– Internet Service Provider (ISP) - connects computers to the
Internet
- Popular commercial ISPs in Kuwait are Quality net, Fasttelco
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Internet Explorer 7 and Firefox 2 Features
 Web browser
– Software that allows the user to view certain types of Internet files in an
interactive environment
– URL (Uniform Resource Locator)
- Each web page on the Internet has unique URL
- Usually begin with http:// or https://
 Hyperlinks
– Visual elements on web pages that when clicked, load a specified web
document
- Images and text
– Can reference other web pages, e-mail addresses, files and more
– Download files
 Tabbed Browsing
– Allows the user to browse multiple pages without many windows
– Page Organization
 Using the History Feature
– List of previously visited URLs in chronological order
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Internet Explorer 7 and Firefox 2 Features
 AutoComplete
– URLs from the history can be displayed in a drop-down list
when a user types a URL into the Address bar
 Off-Line Browsing
– Web pages can be saved directly to the computer’s hard drive
for off-line browsing
- Not connected to the Internet
 Downloads
– Files from the Internet may be copied to a computer’s hard drive
 Viewing Source Code
– Understand how the programmer created the page
– Learn how to develop your own pages
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Fig. 2.1 | Deitel website in Internet Explorer 7.
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Fig. 2.2 | Deitel website in Firefox 2.
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Fig. 2.3 | The History menu in Internet Explorer 7.
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Fig. 2.4 | The History menu in Firefox 2.
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Fig. 2.5 | AutoComplete suggests possible URLs when given a partial address.
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Fig. 2.6 | Saving a picture from a website.
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Customizing Browser Settings
 Browser settings
– Determine how sites are displayed
– How security measures are applied
– How outputs are rendered
 Privacy settings for IE7 and FF2 can be set under the
Privacy tab. In IE7 there are six levels of privacy
– Many levels lenient to strict
 Security options
– Specify how much information you want to hide from unfamiliar
sites
– How much of the site’s content will be blocked from a computer
 Personal home page
– Web page that loads when the browser is first opened
 History options
– Web page cache
– Previously viewed sites
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Fig. 2.7 | Internet Options in Internet Explorer 7.
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Fig. 2.8 | Options in Firefox 2.
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Searching the Internet
 Internet is wealth of information
– Search engines help locate more specific information on a given
topic
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Google (www.google.com)
Yahoo! (www.yahoo.com)
Microsoft (www.bing.com)
MSN (www.msn.com)
Ask.com (www.ask.com)
– Use databases that facilitate quick information retrieval
– Metasearch engines (do not maintain databases)
- Send the search criteria to other search engines and aggregate the
- MetaCrawler (www.metacrawler.com)
– Search engines are good tools for finding information (i.e., can help
resolve programming errors)
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Fig. 2.9 | Searching the Internet with Internet Explorer 7.
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Fig. 2.10 | Searching the Internet with Firefox 2.
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Keeping Track of Your Favorite Sites
 Organize and track Web browsing history (URL
and title)
 Bookmarking
– IE7 - Favorites menu’s
- Favorites can be categorized and grouped into folders
– FF2 – Bookmark This Page... option
 Most browsers have their own version of
Favorites or Bookmarks.
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Fig. 2.11 | The Favorites menu helps organize frequently visited websites in Internet Explorer 7.
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Fig. 2.12 | The Bookmarks menu helps organize frequently visited websites in Firefox 2.
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Online Help
 Built-in help features for browsers
 Answers to frequently asked questions about
using browsers such as FF2 and IE7
– Contents and Index menu item in IE7
– Help Contents in FF2
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Fig. 2.14 | Internet Explorer 7 Help dialog.
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Fig. 2.15 | Firefox 2 Help dialog.
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Other Web Browsers
 All browsers differ in functionality, performance and
features.
 Use different HTML layout engines (determine how a web
page displays in a browser).
 Different browser functionality and features makes crossbrowser compatibility difficult to achieve.