The Internet MCC - CIS105 1 Topics Briefly describe the history of the Internet Describe generally what an Internet service provider does Describe various types techniques used by Internet search sites Describe the various types of e-commerce Describe how advertising is done on the Internet Describe what an intranet is and how a business uses it 2 The Internet and Services The Internet is a worldwide collection of networks used to provide services such as… • • • • • • World Wide Web (WWW) – Websites Email, Instant Messaging (IM) Telephony – Voice over IP (VoIP) Social network, newsgroups, discussion boards File Transfer Protocol (FTP) E-commerce – business transactions For an overview of Making Use of the Web, see pages 116-131 in the textbook Discovering Computers 2008. 3 Internet - many networks connected together 4 Quick Time Line 1969 - ARPANET (Advanced Research Project Agency) • Government sponsored the creation of a network. • Scientists and military shared information. • Network needed to provide alternative paths in case part of the network was destroyed (war). 1972 - E-mail capability added 1973 – The internet went international 1986 - National Science Foundation (NFS) connected its large network, NSFnet, to ARPANET. 1995 – NFS transferred service providing role to private companies. 5 Number of Users 2002 – 567 million users 2003 – 780 million users after 34 years (1969-2003) Compare to… 2005 – US population = 295 million Telephone took 91 years to reach 100 million users. Television took 54 years to reach 100 million users. 6 Number of Sites Another way to measure the growth is by the number websites… 1969 – 4 sites 1971 – 20 sites 1979 – 200 sites 1989 – 100,000 sites 2000 – 72,000,000 sites Why did it grow so much faster between 1989 and 2000? One reason was the number Personal Computers grew. The other was the introduction of the Graphical Browser… 7 Graphical Web Browser A Browser is software used to navigate on the Internet (Internet Explorer, Firefox, etc.). 1990 – Dr. Berners-Lee from Geneva wanted to make the links from one website to another more dynamic and easy using hyperlinks . HyperText Markup Language (HTML) is the language used to create web pages. He described the links like a spider’s web. Hence the name World Wide Web (WWW). 1992 – Marc Andreessen, college student at University of Illinois and Eric J. Bina developed Mosaic – first graphical web browser for multiple platforms. • Graphical browser with hyperlinks and graphics. 1993 – Andreessen and Ken McCarthy developed Netscape. 8 Internet Service Provider (ISP) An Internet Service Provider (ISP) provides the server computer and connection software for companies and individuals to connect to the Internet from their home or business (Earthlink, Qwest, Cox, Hughes, etc). Users at home need a modem to connect to their ISP. Dialup – over phone lines DSL (digital subscriber line) - over phone lines Cable – coaxial and/or fiber optic Fixed Wireless – slow to catch on – Tempe, Chandler Mobile Wireless – cell phones, PDA’s, laptops Satellite - Two modems (uplink and downlink) 9 TCP / IP TCP/IP is the communication standard (protocol) used on the Internet. Transmission Control Protocol (TCP) determines how messages are managed • A message sent over the Internet is divided into uniformly sized packets. • Each packet is labeled with its destination address. • At the destination the message is reassembled using the sequencing information. Internet Protocol (IP) determines how communications software and equipment transport messages. 10 Uniform Resource Locator (URL) A URL is the complete and unique address of a Web page. Web page URL begins with http • HyperText Transfer Protocol Domain name – address of site’s host computer Last part of domain name is called a top-level domain Identifies country and/or purpose of organization URL may include folder and specific filename. http://www.sportsline.com/tennis/index.html Protocol Domain name Path Document name 11 Registering a Domain Name Internet Corporation for Assigned Names and Numbers (ICANN) is the group that assigns and controls toplevel domain names. Outside the United States, the domain name also includes a country code. For example - Australia: www.philips.com.au 12 Domain Name mapped to IP Address An IP address is a unique Numeric Address for each device on the Internet. An IP address consists of four groups of numbers separated with a period. IP Address: http://64.233.167.99/ Domain names are mapped to IP Addresses by a Domain Name Server (DNS). Domain names are meaningful and easier to remember for users. Domain: http://www.google.com/ Search for IP Addresses (use WhoIs Lookup): http://www.dnsstuff.com/ Error 404 – If domain name is not found in DNS. 13 User called Helpdesk because their “Internet connection was not working”. Turns out the user had set the invalid URL as their homepage, so the error page was displayed every time they opened their browser . 14 Web Browser Limitation Browsers can process and display several formats such as HTML, gif, jpeg, JavaScript, etc. However, browsers cannot handle everything. Functionally is increased by using: • Plug-ins • Helpers • Web Programming • See next few slides… 15 Plug-ins / Helpers Software that increases browser functionality Most downloaded from their own Web sites • Once downloaded and installed, it appears as if the browser can handle the new features. • The features are being processed by the plug-ins. Most enhance a site’s audio/visual experience • Flash and QuickTime Players permit viewing sites that include quality animation • Adobe Acrobat Reader displays and prints documents created in Portable Document Format (PDF) format 16 Web Page Programs Small programs can be downloaded to run in your browser • Allow dynamic interaction and dynamic data Scripting languages (Client Side) • Instructions to be interpreted and executed by your browser • JavaScript and VBScript are most common Programming Languages (Client and Server Side) • Java applets and ActiveX controls are most common • Scripting languages that can call programs stored on the server include ASP, JSP, PHP, Perl, and others. May require additional software be installed such as Java Runtime Environment (JRE) Cookies – information that a program stores on your hard disk so that it can remember something about you or your process at a later time. 17 Searching the Internet Search Engine • Lets a user specify simple or complex search criteria. • Search engine then searches the entries in it’s database and returns a list of sites that matches the criteria. • Uses spider software to build database. • Spiders “crawl” throughout websites collecting information – can even find “hidden” files. Trivia - Google was supposed to be Googol, the number 1 followed by 100 zeros Internet directory – list is developed by humans rather than a spider, so entries are very selective (yellowpages). www.mc.maricopa.edu/dept/d07/cis105/searchengines.html 18 Evaluating the Information Author Sources Server (who provides) Objectivity (balanced?) Purpose Accuracy Currency 19 Email Basic Electronic Mail (email) needs… • A server with email services • Users need an account • Need a client application to access the server SPAM is unsolicited e-mail. • The term spam is said to derive from a famous Monty Python sketch. • SPAM is a trademarked Hormel meat product. Phishing is e-mail fraud where the perpetrator sends out legitimate-looking e-mails that appear to come from well known and trustworthy Web sites in an attempt to gather personal and financial information from the recipient (see next slide). 20 Phishing Examples 21 Other Communication Services Social Networks – myspace, facebook NewsGroups – allows posting and reading of messages to a group for everyone to read (discussion board). IRC: Internet Relay Chat • Text Chatting in Real Time to a group, like a party line Instant Messaging – to one person Internet Telephony: Real-Time Voice and Video VoIP – Voice over IP (Internet Protocol) Internet Phone Services (Vonage) 22 File Transfer Protocol (FTP) Allows for upload and download of files. Anonymous FTP • No username or password required. Uploading will most likely require a username and password. Some files are compressed into an archive using a program like WinZip, so the files need to be expanded or extracted after downloading. • Self-extracting is an executable that is doubleclicked to begin file extraction. • If not self-extracting, will need a compatible 23 program to extract files. Homepage / Portal Homepage is the first page displayed when the browser is opened A portal is a website that is supposed to be set as your homepage. Webpage can be personalized so information you are interested in is displayed – stock market, sports, weather May advertise referrals to businesses Yahoo, Google, MySpace, etc. 24 Internet Advertising Many advertisements on Web sites are banner ads Pop-over ads open a new window on top of your current window Pop-under ads open a new window underneath your current window All this advertising is to increase electronic 25 commerce… Electronic Commerce B2B (Business to Business) B2C (Business to Consumer) C2C (Consumer to Consumer) • Ebay.com – watch for fraud • CraigsList.org – Free classified ads Payments – SSL – Secure Sockets Layer ePal is a 3rd party that handles payments. Internet Taxes Freedom Act • No sales tax on out-of-state sales • But usually need to pay shipping Privacy – companies must provide you their privacy policy. 26 Intranets & Extranets An Intranet is a private Internet-like network. Uses the same technology as used for an Internet site. Internal – only computers on the same network may access services – ie: Employee Information Extranets allow selected customers and suppliers to have access to a company’s intranet. EDI – Electronic Data Interchange • Standard format to exchange data (ie: College transcripts, financial data) Can usually identify an Intranet/Extranet when a username and password is required to enter. Access can be restricted using firewalls and IP addresses. • Firewalls – hardware and software 27 Want to Learn More? CIS133DA – Internet / Web Dev CIS235 – e-commerce Certificate of Completion or Two-Year Degree in Web Technology. www.mc.maricopa.edu/dept/d07/degrees.html 28