Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download What is the Internet?
Document related concepts
no text concepts found
Transcript
What is the Internet? Living Online Lesson 2 Objectives Explain the origin of the Internet. Explain how to connect to the Internet from home and school. Explain how the Internet works. List the major features of the Internet and explain what they do. Evolution of the Internet In the Beginning… Department of defense Advanced Research Projects Agency(ARPA). Its mission was to apply state-of-the-art technology to US defense and to avoid being surprised by technological advances of the enemy. It was also given interim control of the US satellite program until the creation of NASA in October 1958. Original name was ARPANET- a computer network system . Next 1969 4 main host nodes (a computer directly connected to the network) were connected • University of California at Santa Barbara • University of California at Los Angeles • Stanford Research Institute • University of Utah 1972 • Email added Major growth 100,000 computers were added in 1989 1990 ARPANET ceased to exist World Wide Web started in 1992 1993 the 1st browser, Mosaic, was released. • Internet access grew 340%. How Do I Get Online? Traditional Ways Accessing the Internet From school • Local Area Network (LAN) • Network Interface Card (NIC) • High speed connection line leased from the local telephone company (T1) • Web Browser Accessing the Internet From home • Modem and a telephone line • Locate Internet Service Provider (ISP) • Install Telecommunications software (allows your computer to talk to another computer) • Install a Web browser Connecting from Home Connect phone line to your modem Install telecommunication software Dial a local telephone number • This number connects to ISP’s computer (server) This computer connects to the Internet Other Internet Connections Other types of Connections Integrated Services Digital Network (ISDN) – uses high speed digital line Digital Subscriber Lines (DSL) – uses high speed digital line Cable modem – uses coaxial cable WebTV – TV acts as monitor to view web pages, uses regular telephone line, black box has modem and hard drive installed to access Internet. Satellite These connections are more expensive than regular dial up. How Does the Internet Work? Think Post Office It’s called interoperability. • A network that connects to other networks that have all brands, models, and makes of computers who communicate with each other. First, you must know the address of where you want to go. You type in the domain name (web site address) • Identifies a site on the Internet The address you typed in is sent from your home PO (ISP) to another computer’s PO (ISP) How it Works Protocol • A standard format for transferring data between 2 devices • The agreed upon international standard for transmitting data: TCP/IP Transmission Control Protocol (TCP) Internet Protocol (IP) Considered the language of the web TCP allows 2 computers to establish a connection and exchange info IP works with the addresses allowing you to send addresses to another computer Major Features The World Wide Web Better known as The Web Subset of the Internet Consists of a collection of electronic files known as web pages Clicking links takes you to another set of files or web site Web began in March 1989 by Tim BernersLee Increased in 1993 when Marc Andreessen released Mosaic—the first graphical Internet browser Web Protocol: http Protocols • HyperText Transfer Protocol (http) indicates a page is a web page Most common one we use to see web pages • File Transfer Protocol (FTP) Used to download or upload files • Gopher • TelNet • And many others Domain: the place (address) where the web pages are loaded protocol + domain = URL • URL – universal resource locator Web Protocol: HTML HyperText Markup Language • Determines how pages are formatted and displayed • A text page with markup tags A Sample Web Text Document <html> <head> <title>Mrs. Elzey's Home Page </title> </head> <body bgcolor=pink><b><center>Internet Skills Home Page</center></b> <br><br><br> <hr> <Font face=Arial size=14 color=blue>I have Internet Skills during periods 1 & 7</font> <br> <br> <p> <ol> <li> <font color=red>apples </font> <li> bananas <li> oranges <li> pears </ol> <img src=car.jpg> <p> <ul> <li> pencils <li> pens <li> crayons <li> markers </ul> </body> </html> E-Mail Stands for Electronic Mail • A way to send electronic messages from 1 computer to another • Can include attachments such as pictures, sounds, video, or documents Each address is unique and consists of 3 parts: • User name •@ • User’s domain name (the name of the server where you e-mail is stored until you retrieve it) Protocol • Username + @ + domain name Chat Rooms Real-time communication between yourself and another person or persons A virtual world Like being on the phone but instead of hearing them you must read what is being said. Several chat forums available. • • • • AOL Instant Message Internet Relay Chat Yahoo ICU Game Mailing Lists A group of people with a shared interest Email messages are collected in a group You send a message to one address Everyone in the group receives the same message Magazines and others use this to get subscribers Type of mailing lists include: • • • • Announcements Discussions Public and private lists Digest versions Newsgroups Discussion forum or type of bulletin board You select the topic you want to read from many topics available You must have a newsreader to participate in a newsgroup USENET facilitates the transmission of messages among the news servers The protocol that makes this possible is NNTP. There are over 50,000 and the number is increasing each day. Easy to navigate because they are organized by subject. File Transfer Protocol FTP allows users to download and upload files to and from computers on the Internet Some require passwords and user Ids. File compression reduces the size of a file so it can download or upload faster. WS_FTP is one example that is free to students and educational institutions.
