E-Business Tenth Edition Chapter 2 E-Business Technology Basics 1 1

The Internet and the World Wide Web Computer network Technology allowing people to connect computers Internet Interconnected global computer networks (large) Basic technology structure Computer networks and the Internet Underlies e-commerce World Wide Web (Web) Subset of Internet computers Contents easily accessible Includes easy-to-use interfaces E-Business, tenth Edition 2

Packet-Switched Networks Local area network (LAN) Network of computers located close together Wide area networks (WANs) Networks of computers connected over greater distances Circuit Combination of telephone lines and closed switches that connect them to each other Circuit switching Centrally controlled, single-connection model Single electrical path between caller and receiver E-Business, tenth Edition

Packet-Switched Networks (cont’d.) Circuit switching (cont’d.) Works well for telephone calls Does not work as well for: Sending data across large WAN, interconnected network (Internet) Circuit-switched network problem Connected circuit failure Causes interrupted connection, data loss Solution Packet switching: move data between two points E-Business, tenth Edition

Packet-Switched Networks (cont’d.) Small pieces labeled electronically (origin, sequence, destination address) Travel along interconnected networks Can take different paths May arrive out of order Destination computer Collects packets Reassembles original file or e-mail message E-Business, tenth Edition

Intranets & Extranets Intranet: Inter connected networks inside an organization VPN is used to form intranet over the public networks using a technology called IP tunneling IP tunneling creates a private passageway. It transfers the packets encrypted Extranet: Networks between the organizations i.e. business partners, customers, suppliers. A cheaper option than fax, express document carriers VPN is used to secure the networks Web is used as part of the extranet and intranet E-Business, tenth Edition

TCP/IP Internet protocols Transmission Control Protocol (TCP) -establishes a connection between the computers -sequences the transfer of packets -acknowledges the packets sent Internet Protocol (IP) -responsible for delivery of the packets -includes disassembling and reassembling of packets during transmission E-Business, tenth Edition

IP Addressing Internet Protocol version 4 (IPv4) IP address Can provide 4 billion different addresses IP address 32-bit number identifying computers Byte (8-bit number) Octet (networking applications) Binary values: 00000000 to 11111111 Decimal equivalents: 0 to 255 E-Business, tenth Edition

IP Addressing (cont’d.) Dotted decimal notation IP numbers (addresses) Four numbers separated by periods Four parts range from 0 to 255 IP addresses range: 0.0.0.0 to 255.255.255.255 Three organizations assign IP addresses: ARIN (Americas), RIPE (Europe), ACNIC (Asia Pacific) Whois server (by ARIN) Returns IP address list owned by an organization E-Business, tenth Edition

Electronic Mail Protocols Electronic mail (e-mail) Formatted according to common set of rules Client/server structure E-mail server Computer devoted to e-mail handling Stores, forwards e-mail messages E-mail client software Read and send e-mail Communicates with e-mail server Standardization and rules very important: SMTP & POP E-Business, tenth Edition

Electronic Mail Protocols (cont’d.) Two common protocols Simple Mail Transfer Protocol (SMTP) Specifies mail message format Administers e-mail on e-mail server Transmits mail from server to client Post Office Protocol (POP) Sends mail to user’s computer from server Store mail to user’s email client software Asks if new mail arrived E-Business, tenth Edition

Electronic Mail Protocols (cont’d.) Example: Suppose you use Gmail server to send email to bill@microsoft.com You click send on email client Gmail Gmail client delivers email to Gmail server using SMTP Gmail server delivers email to Microsoft’s email server, mail.microsoft.com, using SMTP Bill’s email client download the email from the Microsoft’s email server using POP E-Business, tenth Edition

Web Page Request and Delivery Protocols Hypertext Transfer Protocol (HTTP) Internet Web page file delivery rules from Web servers Web page request using Web browser Type of protocol name followed by “//:” before domain name Uniform Resource Locator (URL) Combination: protocol name, domain name Locate resource (Web page) on another computer (Web server) E-Business, tenth Edition

Emergence of the World Wide Web (cont’d.) Graphical interfaces for hypertext Web browser Software interface Users read (browse) HTML documents Move from one HTML document to another Text formatted with hypertext link tags in file HTML document No specification of text element appearance Graphical user interface (GUI) Presents program control functions, output to users Pictures, icons, other graphical elements E-Business, tenth Edition

Domain Names Dotted decimal notation difficult to remember Sets of words assigned to specific IP addresses Example: www.sandiego.edu Contains three parts separated by periods Top-level domain (TLD): rightmost part Generic top-level domains (gTLDs) Sponsored top-level domains (sTLD) Internet Corporation for Assigned Names and Numbers (ICANN) Responsibility: managing non-sTLD E-Business, tenth Edition

E-Business, tenth Edition

Markup Languages and the Web Text markup language Specifies tag set inserted into text Markup tags (tags) Formatting instructions Web client understands HTML Web markup language Most commonly used Standard Generalized Markup Language (SGML) subset Older, more complex text markup language E-Business, tenth Edition

Markup Languages and the Web (cont’d.) Extensible Markup Language (XML) Derived from SGML Mark up shared information with another company World Wide Web Consortium (W3C) Maintains Web standards Extensible Hypertext Markup Language (XHTML) HTML version 4.0 reformulation as XML application E-Business, tenth Edition

E-Business, tenth Edition

Hypertext Markup Language Hypertext elements Text elements related to each other HTML Prevalent markup language to create Web documents W3C HTML Working Group page Detailed HTML versions, related topic information HTML extensions Features that work in specific Web browsers E-Business, tenth Edition

Hypertext Markup Language (cont’d.) HTML tags Interpreted by Web browser Format text display Enclosed in angle brackets (<>) Opening tag and closing tag Format text between them Closing tag Preceded by slash within angle brackets (</>) User may customize tag interpretations Tags: lowercase or uppercase letters E-Business, tenth Edition

Hypertext Markup Language (cont’d.) One-sided tags Require opening tag only Two-sided tags Optional closing tag Closing tag position very important Opening tag may contain one or more property modifiers Further refine tag operation Other frequently used HTML tags Graphics and tables E-Business, tenth Edition

E-Business, tenth Edition

E-Business, tenth Edition

Hypertext Markup Language (cont’d.) HTML links Hyperlinks form interlinked pages that form a “web” Linear hyperlink structure Read Web page in serial fashion Good for when customer fills out form Hierarchical hyperlink structure Introductory page (home page, start page) links to other pages Leads customers from general to specific topics Hybrid designs combine linear and hierarchical structures E-Business, tenth Edition

E-Business, tenth Edition

E-Business, tenth Edition

Extensible Markup Language (XML) Web design tool Web pages contain large amounts of data, lists Includes data-management capabilities HTML cannot provide See Figures 2-10 and 2-11 Illustrate HTML shortcomings in presenting lists XML different from HTML XML is not a markup language with defined tags XML tags do not specify text appearance on page E-Business, tenth Edition

E-Business, tenth Edition

E-Business, tenth Edition

Figures 2-12 and 2-13 Advantages of XML list presentation More effectively communicate the meaning of data E-Business, tenth Edition

E-Business, tenth Edition

Extensible Markup Language (XML) (cont’d.) Strength of XML Allows users to define their own tags (weakness as well) XML files not intended to display in browser Extensible Stylesheet Language (XSL) Contains formatting instructions XML parsers: format XML file for device screen E-Business, tenth Edition

E-Business, tenth Edition

HTML and XML Editors HTML document creation XML files General-purpose text editor or word processor Special-purpose HTML editors Freeware, shareware, commercial Web site design tools Create and manage complete Web sites Upload entire site from PC to Web server Example: Adobe Dreamweaver XML files Created with text editor or programs E-Business, tenth Edition