Review Question : 3
3Q) How do the Internet and Internet technology work, and how do they support communication and e-business? Ans) The Internet is a worldwide network of networks that uses the client/server model of computing and the TCP/IP network reference model. Every computer on the Internet is assigned a unique numeric IP address. The Domain Name System (DNS) converts IP addresses to more user-friendly domain names. Worldwide Internet policies are established by organizations and government bodies, such as the Internet Architecture Board (IAB) and the World Wide Web Consortium (W3C).
•Define the Internet, describe how it works, and explain how it provides business value. The Internet has become the world’s most extensive, public communication system that now rivals the global telephone system in reach and range. Most homes and small businesses connect to the Internet by subscribing to an Internet service e provider. An Internet service provider (ISP) is a commercial organization with a permanent connection to the Internet that sells temporary connections to retail subscribers.
•Explain how the Domain Name System (DNS) and IP addressing system work. It would be incredibly difficult for Internet users to remember strings of 12 numbers; the Domain Name System (DNS) converts domain names to IP addresses. The domain name is the English-like name that corresponds to the unique 32-bit numeric IP address for each computer connected to the Internet. DNS servers maintain a database containing IP addresses mapped to their corresponding domain names. To access a computer on the Internet, users need only specify its domain name. DNS has a hierarchical structure. At the top of the DNS hierarchy is the root domain. The child domain of the root is called a top-level domain, and the child domain of a top-level domain is called is a second-level domain. The Internet is based on the TCP/IP networking protocol suite. Every computer on the Internet is assigned a unique Internet Protocol (IP) address, which currently is a 32-bit number represented by four strings of numbers ranging from 0 to 255 separated by periods. When a user sends a message to another user on the Internet, the message is first decomposed into packets using the TCP protocol. Each packet contains its destination address. The packets are then sent from the client to the network server and from there on to as many other servers as necessary to arrive at a specific computer with a known address. At the destination address, the packets are reassembled into the original message.
•List and describe the principal Internet services.
A client computer connecting to the Internet has access to a variety of services. These services include e-mail, electronic discussion groups, chatting and instant messaging, Telnet, File Transfer Protocol (FTP), and the Web. E-mail:
E-mail enables messages to be exchanged from computer to computer, with capabilities for routing messages to multiple recipients, forwarding messages, and attaching text documents or multimedia files to messages. Although some organizations operate their own internal electronic mail systems, most e-mail today is sent through the Internet. The costs of e-mail is far lower than equivalent voice, postal, or overnight delivery costs, making the Internet a very inexpensive and rapid communications medium. Chatting:
Many workplaces have employees communicating interactively using chat or instant messaging tools. Chatting enables two or more people who are simultaneously connected to the Internet to hold live, interactive conversations. Chat systems now support voice and video chat as well as written conversations. Many online retail businesses offer chat services on their Web sites to attract visitors, to encourage repeat purchases, and to improve customer service. Instant Messaging:
Instant messaging is a type of chat service that enables participants to create their own private chat channels....