1. THE INTERNET Began as a U.S Department of Defense network to link scientists and university professors around the world.Began as a U.S Department of Defense network to link scientists and university professors around the world. No individual can connect directly to the Net, he can access it through an Internet Service Provider.No individual can connect directly to the Net, he can access it through an Internet Service Provider. INTERNET SERVICE PROVIDER (ISP): organization connected permanently to the internet, leases temporary connections to subscribers.INTERNET SERVICE PROVIDER (ISP): organization connected permanently to the internet, leases temporary connections to subscribers. No one owns it.No one owns it. I has no formal management organization.I has no formal management organization.

2. THE INTERNET As a creation of the Defense Department for sharing research data, this lack of centralization made it less vulnerable to wartime or terrorist attacks.As a creation of the Defense Department for sharing research data, this lack of centralization made it less vulnerable to wartime or terrorist attacks. To join the Internet, an existing network needs only to pay a small registration fee and agree to certain standards based on the TCP/IP reference model.To join the Internet, an existing network needs only to pay a small registration fee and agree to certain standards based on the TCP/IP reference model.

3. THE INTERNET Costs are low because the internet owns nothing and so has no costs to offset.Costs are low because the internet owns nothing and so has no costs to offset. Each organization pays for its own networks and its own telephone bills, however those costs usually are independent of the Internet.Each organization pays for its own networks and its own telephone bills, however those costs usually are independent of the Internet. Regional Internet companies have been established to which member networks forward all transmissions.Regional Internet companies have been established to which member networks forward all transmissions. These Internet companies route and forward all traffic, and the cost is still only that of a local telephone call.These Internet companies route and forward all traffic, and the cost is still only that of a local telephone call.

4. THE INTERNET The Internet is based on the Client/server technology.The Internet is based on the Client/server technology. Individuals using the Net control what they do through client applications such as Web browser software.Individuals using the Net control what they do through client applications such as Web browser software. All the data, including e-mail message and Web pages are stored on servers.All the data, including e-mail message and Web pages are stored on servers. A client uses the Internet to request information from a particular Web server on a distant computer, and the server sends the requested information back to the client via the Internet.A client uses the Internet to request information from a particular Web server on a distant computer, and the server sends the requested information back to the client via the Internet.

5. THE INTERNET Web server software receives requests for Web pages from the client and accesses the Web pages from the disk where they are stored.Web server software receives requests for Web pages from the client and accesses the Web pages from the disk where they are stored. Web servers can also access other information from an organization’s internal information system applications and their associated databases and return that information to the client in the form of Web pages if desired.Web servers can also access other information from an organization’s internal information system applications and their associated databases and return that information to the client in the form of Web pages if desired. Specialized middleware, including application servers and custom programs, is used to manage the interaction between the Web server and the organization’s internal information systems for processing orders, tracking inventory, etc.Specialized middleware, including application servers and custom programs, is used to manage the interaction between the Web server and the organization’s internal information systems for processing orders, tracking inventory, etc.

6. INTERNET CAPABILITIES E -MAIL: person -to-person messaging; document sharingE -MAIL: person -to-person messaging; document sharing USERNET NEWSGROUPS: electronic bulletin boards for discussion groupsUSERNET NEWSGROUPS: electronic bulletin boards for discussion groups LISTSERVs: e-mail list servers for discussion groupsLISTSERVs: e-mail list servers for discussion groups CHATTING: interactive conversationsCHATTING: interactive conversations TELNET: log on one computer, work on anotherTELNET: log on one computer, work on another FTP: transfer files from computer to computerFTP: transfer files from computer to computer GOPHERS: use menus to locate text materialGOPHERS: use menus to locate text material

7. INTERNET CAPABILITIES ARCHIE: search database for files to downloadARCHIE: search database for files to download VERONICA: speeds searching gopher sites by using keywordsVERONICA: speeds searching gopher sites by using keywords WIDE AREA INFORMATION SERVICE (WAIS): locates files using key wordsWIDE AREA INFORMATION SERVICE (WAIS): locates files using key words WORLD WIDE WEB: retrieve, format, display information (text, audio, graphics, video) using hypertext linksWORLD WIDE WEB: retrieve, format, display information (text, audio, graphics, video) using hypertext links

8. INTERNET ADDRESS ggalileo@univpisa.edu.it INDIVIDUAL OR ORGANIZATION NAME HOST COMPUTER LOCATION FUNCTION DOMAIN NAME

9. INTERNET TERMS HOME PAGE: WWW screen display welcomes user to organization’s pageHOME PAGE: WWW screen display welcomes user to organization’s page WEBMASTER: person in charge of Web siteWEBMASTER: person in charge of Web site UNIFORM RESOURCE LOCATOR (URL): address of specific Internet resourceUNIFORM RESOURCE LOCATOR (URL): address of specific Internet resource

10. INTERNET TERMS HYPERTEXT TRANSPORT PROTOCOL (http): communications standard (sets of rules) used to transfer Web pages.HTTP defines how messages are formatted and transmitted and what actions Web servers and browsers should take in response to various commands.HYPERTEXT TRANSPORT PROTOCOL (http): communications standard (sets of rules) used to transfer Web pages.HTTP defines how messages are formatted and transmitted and what actions Web servers and browsers should take in response to various commands. HYPERTEXT MARKUP LANGUAGE (HTML): popular programming language for creating Web sitesHYPERTEXT MARKUP LANGUAGE (HTML): popular programming language for creating Web sites

11. SURFING THE NET SEARCH ENGINE: tool for locating specific sites or information on WWWSEARCH ENGINE: tool for locating specific sites or information on WWW “PUSH” TECHNOLOGY: server streams Web page content to a Web browser“PUSH” TECHNOLOGY: server streams Web page content to a Web browser HYPERLINK: spot on screen, when clicked shifts to a new page or siteHYPERLINK: spot on screen, when clicked shifts to a new page or site

12. “Push” Technology Instead of surfing the Web, users can have the information they are interested is delivered automatically to their desktops through “push’ technology.Instead of surfing the Web, users can have the information they are interested is delivered automatically to their desktops through “push’ technology. A computer broadcasts information of interest directly to the user, rather than having the user “pull’ content from Web sites.A computer broadcasts information of interest directly to the user, rather than having the user “pull’ content from Web sites. “Push” comes from server push, a term used to describe the streaming of Web page contents from a Web server to a Web browser“Push” comes from server push, a term used to describe the streaming of Web page contents from a Web server to a Web browser Special client software allows the user to specify the categories of information he wants to receive and how often this information should be updated.Special client software allows the user to specify the categories of information he wants to receive and how often this information should be updated.

13. “Push” Technology Push program will notify the user by sending e- mail, playing a sound, displaying an icon on the desktop, sending full article or Web pages, or displaying headlines on screen saver.Push program will notify the user by sending e- mail, playing a sound, displaying an icon on the desktop, sending full article or Web pages, or displaying headlines on screen saver. Examples:Examples: Fruit of the Loom is using Pointcast push technology to alert managers to updated inventory information stored on its IBM AS/400 intranet Web server.Fruit of the Loom is using Pointcast push technology to alert managers to updated inventory information stored on its IBM AS/400 intranet Web server. Lufthansa uses the BackWeb push delivery service to alert customers to fare discount.Lufthansa uses the BackWeb push delivery service to alert customers to fare discount.

14. INTRANET INTERNAL NETWORK: A simple intranet can be created by linking a client computer with Web browser to a computer with Web server software via a TCP/IP networkINTERNAL NETWORK: A simple intranet can be created by linking a client computer with Web browser to a computer with Web server software via a TCP/IP network Intranet software technology is same as that of the WWW TECHNOLOGY.Intranet software technology is same as that of the WWW TECHNOLOGY. FIREWALL: Security System (consists of hardware and software placed between an organization’s internal network and an external network, including the Internet) to Prevent Invasion of Private NetworksFIREWALL: Security System (consists of hardware and software placed between an organization’s internal network and an external network, including the Internet) to Prevent Invasion of Private Networks Overcomes computer platform differences.Overcomes computer platform differences. Often installed on existing network infrastructure.Often installed on existing network infrastructure.

15. EXTRANET Allows authorized users outside organization to use its Intranet: CustomersCustomers Business partnersBusiness partners VendorsVendors

16. EXTRANET INTERNET CUSTOMERSUPPLIER FIREWALL DATABASES SERVER CLIENTS BUSINESS PARTNER

17. INTERNET BENEFITS Global connectivityGlobal connectivity Reduced communications costReduced communications cost Lower transaction costsLower transaction costs Reduced agency costsReduced agency costs Interactivity, flexibility, customizationInteractivity, flexibility, customization Accelerated knowledgeAccelerated knowledge

18. Components of an Internet server SMTPFTP DNS Client Access WAIS/ RDBFE WWW Server Authorizing Tools Back/End Database Network TCP/IP Stack Network Operating system Server Box Internet InterfaceFirewall/Router Internet Service Provider

19. Components of an Internet server SMTP: The Simple Mail Transfer Protocol utility translates between local and Internet mail formats, allowing clients to send/receive Internet e-mail. FTP: The File Transfer Protocol utility enables file transfers to and from the server. DNS: The Domain Name Serving Utility maps numerical Internet machine addresses (161.362.456.567) to alphabetic names (systems.compaq.com). Client Access : The Client Access software allows local clients to use the Internet (Web, FTP, etc.) over the existing network. WAIS/RDBFE: The Wide Area Information Service and Relational Database Front End Software allows Web site guests to access document database without requiring HTML encoding beforehand. WAIS is the most thorough way to locate a specific file, however, you have to know the name of the databases you want to search. WWW Server: The WWW Server Software serves Web pages to guests and helps to administrate the Web site. Authoring Tools: Authoring Tools create the pages that appear on the Web site.

20. Components of an Internet server Back/End Database : The Back/End Database is an Oracle, Sybase, or Back Office database that contains content served to the Web via the RDBFE and WWW Server Network TCP/IP: The TCP/IP stack allows the NOS to communicate via the Internet protocol in addition to its native protocol. Network Operating System: The Network Operating System is UNIX, Netware, or NT. Server Box : The server Box houses the CPU, disks, and Ethernet I/O hardware. Internet Interface: The Internet Interface is a WAN card that connects the server to the leased line provided by the Internet Service Provider (ISP). These cards can be Installed in a separate firewall/router box or on the server itself. Firewall/Router: The Firewall/Router sorts and filters data passing to and from the Internet. This functionality is performed by software either installed on the server itself or on a separate box. Internet Service Provider : The Internet Service Provider provides an Ip address, works through the local telephone company to arrange for a leased line, and provides installation and administration consulting services.