Introduction to Internet, WWW, and Web browsers

Internet and World Wide Web 1 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)

Internet

Internet Many different services runs on the Internet 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.

World Wide Web (WWW) What is WWW or Web? The 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.

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

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.

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

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.

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.

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.

Full Stack Web Development ISC340 ISC440

Full Stack Web Development

Web Browser Basics: Internet Explorer and Firefox 2 Web Browser Basics: Internet Explorer and Firefox

Introduction to the Internet Explorer 7 and Firefox 2 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 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

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 high-speed Internet connection. Internet Service Provider (ISP) - connects computers to the Internet Popular commercial ISPs in Kuwait are Quality net, Fasttelco

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

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

Fig. 2.1 | Deitel website in Internet Explorer 7.

Fig. 2.2 | Deitel website in Firefox 2.

Fig. 2.3 | The History menu in Internet Explorer 7.

Fig. 2.4 | The History menu in Firefox 2.

Fig. 2.5 | AutoComplete suggests possible URLs when given a partial address.

Fig. 2.6 | Saving a picture from a website.

Customizing 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

Fig. 2.7 | Internet Options in Internet Explorer 7.

Fig. 2.8 | Options in Firefox 2.

Searching the Internet Internet is wealth of information Search engines help locate more specific information on a given topic 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)

Fig. 2.9 | Searching the Internet with Internet Explorer 7.

Fig. 2.10 | Searching the Internet with Firefox 2.

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.

Fig. 2.11 | The Favorites menu helps organize frequently visited websites in Internet Explorer 7.

Fig. 2.12 | The Bookmarks menu helps organize frequently visited websites in Firefox 2.

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

Fig. 2.14 | Internet Explorer 7 Help dialog.

Fig. 2.15 | Firefox 2 Help dialog.

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 cross-browser compatibility difficult to achieve.