Communication, Networks, The internet and the Worldwide Web

The Internet What is a network?  A collection of computers and devices connected together via communications devices and media Modems Cables Telephone lines Satellites

message board instant messaging file transfer Web The Internet What are some of the services found on the Internet? chat p. 2.3 Fig. 2-1 Next

Goal: To function even if part of the network were disabled or destroyed Became functional in September 1969 Goal: To allow scientists at different locations to share information and work together on military and scientific projects History of the Internet How did the Internet originate? ARPANET Networking project by Pentagon ’ s Advanced Research Projects Agency (ARPA)

Government Cable companies Satellite companies Telephone companies History of the Internet Who provides the structure for the Internet today? Networks from corporations, commercial firms, and other companies

World Wide Web Consortium (W3C) Oversees research and sets standards and guidelines Internet2 (I2) Internet-related research and development project Develops and tests advanced Internet technologies History of the Internet Who controls the Internet?  The Internet is a public, cooperative, and independent network  No single entity controls or owns the Internet  Several organizations advise and define standards

High speed connection Employees and students Computers part of a local area network (LAN) Connect to service provider through a high-speed connection line leased from local telephone company How the Internet Works How can you connect to the Internet? Dial-up access Home or small business Computer, modem, regular telephone line Dial into an ISP or OSP Newer high-speed technologies Home and small business Digital subscriber line (DSL) – provides high-speed Internet connections over regular copper telephone line Cable modem- provides high-speed Internet connections through cable television network

How might data travel the Internet using a telephone line connection? Step 1 Step 2 Step 1 Step 2 Step 3 Step 1 Step 2 Step 3 Step 4 Regional ISP Step 1 Step 2 Step 3 Step 4 Step 5 Regional ISP National ISP Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Regional ISP National ISP Internet backbone Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Regional ISP Local ISP National ISP Internet backbone How the Internet Works Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Regional ISP Local ISP National ISP Internet backbone 1: You initiate an action to request data from the Internet. 2: A modem converts the digital signals from the computer into analog signals, which are understood by telephone lines. 3: Data (request) travels through telephone lines to a local ISP. 4: Data may pass through one or more routers before reaching its final destination. 5: The regional ISP uses lines, leased from a telephone company, to send data to a national ISP. 6: The national ISP routes data across the country to another national ISP. 7: Data moves from a national ISP to a local ISP and then to a destination server. 8: The server retrieves the requested data and sends it back through the Internet backbone to your computer.

How the Internet Works What is an Internet protocol (IP) address?  Number that uniquely identifies each computer or device connected to the Internet  Four groups of numbers, each separated by a period  Number in each group is between 0 and 255 IP address first part identifies network last part identifies specific computer

How the Internet Works What is a domain name?  Text version of an IP address  Components are separated by periods  Each domain name represents one or more IP addresses IP address Domain name

How the Internet Works What is a top-level domain (TLD) abbreviation?  Identifies the type of organization associated with the domain  Sometimes called dot com when TLD is com

Internet Corporation for Assigned Names and Numbers (ICANN) Group that assigns and controls TLDs How the Internet Works What systems control domain names? Domain name system (DNS) System on the Internet that stores the domain names and their corresponding IP addresses DNS server Translates the domain name into its associated IP address

The World Wide Web What is the World Wide Web (WWW)?  Also known as the Web  A worldwide collection of electronic documents  Each document on the Web is called a Web page  Can contain text, graphics, sound, and video  Can contain built-in connections to other documents  A Web site is a collection of related Web pages

The World Wide Web What is a Web browser?  Also called a browser  Software program that allows you to access and view Web pages  Two popular browsers for personal computers Netscape Internet Explorer

 The activity of jumping from one Web page to another is surfing The World Wide Web What is surfing the Web?  Links can point to an item on the same Web page, a different Web page at the same Web site, or a separate Web page at a different Web site in another city or country

The World Wide Web What are the parts of a URL? protocoldomain namepath

Web Publishing Hardware Digital camera Scanner Sound card Microphone PC camera What is needed for creating a Web page?  Also called Web page authoring Software to prepare HTML HTML (hypertext markup language) A set of special codes that format a file for use as a Web page Created with either: Word processing package Web page authoring software

Upload, or copy, the site to the Web server Locate a Web server to store your site Provided by many ISPs and OSPs at no additional cost Provided by a Web hosting service for a monthly fee Web Publishing How do you deploy a Web site?

Apply to an official registrar for a specific domain name Register site with search engines using a submission service A Web-based business that helps register your site Webmaster Individual responsible for maintaining a Web site and developing Web pages Web Publishing What else might be needed to create a Web site?

Other Internet Services What is ?  Electronic mail  The transmission of messages and files via a computer network  Use an program to work with messages createreceivestoreprintsendforwarddelete

Step 1 Step 2 Step 1 Step 2 Step 3 Step 1 Step 2 Step 3 Step 4 How do you send an message? Other Internet Services Step 1 Step 2 Step 3 Step 4 Step 5 1Start an program and point to the New Mail Message button 2Click the New Mail Message button to display the Message window 3Enter the recipient ’ s address, the subject, and the message in the Message window 4Click the Insert File button to attach a JPG file containing a picture to the message. Locate the file on your hard disk and click its name. An icon for the file displays. Click the Send button to send the message. 5When Sally receives the e- mail message, she opens the JPG file to view the picture.

Other Internet Services What is an Internet address?  A combination of a user name and a domain name that identifies a user so he or she can receive Internet user name or user-ID A unique combination of characters that identifies you at domain name Identifies the mail server

mail server The server that contains the mailboxes Other Internet Services How can you get ?  Most ISPs and OSPs provide an Internet program and a mailbox on a mail server as a standard part of their Internet access services  Some Web sites provide services free of charge address book Allows you to store a list of names and addresses mailbox Storage location usually residing on the computer that connects you to the Internet

Other Internet Services file download window What is FTP?  File Transfer Protocol  An Internet standard that allows you to upload and download files with other computers on the Internet