chapter 2.pdf
- 2. What is the “internet”? ● The Internet is a global information network that connects millions of computers It is growing exponentially and provides a unique information resource that is global, diverse and current.
- 3. What do we use the internet for? ● Browsing information ● Social media and creating awareness ● For entertainment (music, videos, movies) ● Communicating with people all over the world. ● Sharing information ● E-commerce and banking
- 4. Internet in the 1950’s ● The Internet has no single “inventor.” Instead, it has evolved over time. ● The Internet got its start in the United States more than 50 years ago as a government weapon in the Cold War.
- 5. Contd. ● Scientists and researchers used it to communicate and share data with one another through what was known as DARPNET(Defense’s Advanced Research Projects Agency Network). ● This was in response to the Soviet Union bombings and a need to create a communication network which was free from interference and disruption.
- 6. Internet in the 1960’s ● In 1962, a scientist from M.I.T. and DARPA named J.C.R. Licklider proposed : a “galactic network” of computers that could talk to one another. Such a network would enable government leaders to communicate even if the Soviets destroyed the telephone system. ● In 1965, another M.I.T. scientist developed a way of sending information from one computer to another that he called “packet switching.” Packet switching breaks data down into blocks, or packets, before sending it to its destination.
- 7. Contd. ● Without packet switching, the government’s computer network—now known as the ARPANET—would have been just as vulnerable to enemy attacks as the phone system. ● In 1969, ARPANET delivered its first message: a “node-to-node” communication from one computer to another but it crashed the full network. The internet was yet to be born
- 8. Internet in the 1970’s ● By the end of 1969, just four computers were connected to the ARPANET, but the network grew steadily during the 1970s. ● As packet-switched computer networks multiplied, however, it became more difficult for them to integrate into a single worldwide “Internet.”
- 9. Contd. ● By the end of the 1970s, a computer scientist named Vinton Cerf had begun to solve this problem by developing a way for all of the computers on all of the world’s mini-networks to communicate with one another. ● He called his invention “Transmission Control Protocol,” or TCP. (Later, he added an additional protocol, known as “Internet Protocol.” The acronym we use to refer to these today is TCP/IP .)
- 10. Contd. ● TCP/IP was described to be the “handshake” between computers all over the world. It enabled each computer to have its own identity.
- 11. Internet in the 1980’s ● Cerf’s protocol transformed the Internet into a worldwide network. Throughout the 1980s, researchers and scientists used it to send files and data from one computer to another. ● However , this network was still between scientists and researchers from different universities and labs.
- 12. Internet in the 1990’s ● However, in 1991 the Internet changed again. ● Tim Berners-Lee introduced the World Wide Web: an Internet that was not simply a way to send files from one place to another but was itself a “web” of information that anyone on the Internet could retrieve. ● Berners-Lee created the first browser and the Internet that we know today.
- 13. Contd. ● In 1992, a group of students and researchers at the University of Illinois developed a sophisticated browser that they called M osaic. (It later became Netscape.) ● Mosaic offered a user-friendly way to search the Web: It allowed users to see words and pictures on the same page for the first time and to navigate using scrollbars and clickable links.
- 14. Contd. ● That same year, Congress decided that the Web could be used for commercial purposes. As a result, companies of all kinds hurried to set up websites of their own, and e-commerce entrepreneurs began to use the Internet to sell goods directly to customers. ● More recently, social networking sites like Facebook have become a popular way for people of all ages to stay connected.
- 15. ARPANET The original ARPANET consisted of four main computers, one each located; at the University of California at Los Angeles, the University of California at Santa Barbara, the Stanford Research Institute, and the University of Utah. Each of these computers served as a host on the network. A host or server:- is any computer that provides services and connections to other computers on a network. No single person, company, institution, or government agency controls or owns the Internet. • The World Wide Web Consortium (W3C), however, oversees research and sets standards and guidelines for many areas of the Internet. • More than 350 organizations from around the world are members of the W3C
- 16. Connecting to the Internet Many home and small business users connect to the Internet via high-speed broadband Internet service. With broadband Internet service, your computer or mobile device usually is connected to the Internet the entire time it is powered on. Examples of broadband Internet service include the following: • Cable Internet service provides high-speed Internet access through the cable television network via a cable modem. • DSL (digital subscriber line) provides high-speed Internet connections using regular telephone lines. • Fibber to the Premises (FTTP) uses fibber-optic cable to provide high-speed Internet access to home and business users. • Fixed wireless provides high-speed Internet connections using a dish-shaped antenna on your house or business to communicate with a tower location via radio signals. • A Wi-Fi (wireless fidelity) network uses radio signals to provide high-speed Internet connections to wireless computers and devices. • A cellular radio network offers high-speed Internet connections to devices with built-in compatible technology or computers with wireless modems. • Satellite Internet service provides high-speed Internet connections via satellite to a satellite dish that communicates with a satellite modem.
- 17. Access Providers An access provider is a business that provides individuals and organizations access to the Internet free or for a fee. For example, some Wi-Fi networks provide free access while others charge a per use fee. 1. ISP (Internet service provider) is a regional or national access provider. • A regional ISP usually provides Internet access to a specific geographic area. • A national ISP is a business that provides Internet access in cities and towns nationwide. • National ISPs usually offer more services and have a larger technical support staff than regional ISPs. • Examples of national ISPs are Somcable. 2. online service provider (OSP) also has many members-only features such as instant messaging or their own customized version of a Web browser. • The two more popular OSPs are AOL (America Online) and MSN (Microsoft Network). • AOL also provides free access to its services to any user with a high-speed Internet connection. 3. wireless Internet service provider, sometimes called a wireless data provider, is a company that provides wireless Internet access to computers and mobile devices, • such as smart phones and portable media players with built-in wireless capability (such as Wi-Fi) or • to computers using wireless modems or wireless access devices.
- 18. Internet Addresses An IP address, short for Internet Protocol address, is a number that uniquely identifies each computer or device connected to the Internet. • The IP address usually consists of four groups of numbers, each separated by a period. In general, the first portion of each IP address identifies the network and the last portion identifies the specific computer. A domain name is the text version of an IP address. Web Addresses A Web page has a unique address, which is called a URL (Uniform Resource Locator) or Web address. For example, Somaliland government Web site has a Web address of Government of Somaliland (govsomaliland.org) A Web browser retrieves a Web page using its Web address.
- 19. searching the Web Two types of search tools are search engines and subject directories. 1. A search engine is a program that finds Web sites, Web pages, images, videos, news, maps, and other information related to a specific topic. 2. A subject directory classifies Web pages in an organized set of categories or groups, such as sports or shopping, and related subcategories.
- 20. Types of Web Sites Thirteen types of Web sites are; • portal, • news, • informational, • business/marketing, • blog, • wiki, • online social network, • educational, • entertainment, • advocacy, • Web application, • content.
- 21. Thank you!