Definition

"The Internet is a rapidly growing network of thousands of business, educational, and research networks connecting millions of computers and their users in over 100 countries." (O’Brien, 2001, p. G-12)

Characteristics and Components

"Packet-switched networks move data in separate small blocks – packets – based on the destination address in each packet. When received, packets are reassembled in the proper sequence to make up the message. Circuit-switched networks require dedicated point-to-point connections during calls." (Copeland, 2000, p. 74) The Internet is a packet-switched network.

ISP (Internet Service Provider) - A company that provides access to the Internet, usually for a monthly fee. ISPs may provide access through dial-up lines or higher speed connections. An ISP may also provide e-mail, web pages, and a portal in addition to Internet access. ISPs interconnect through NAPs (Network Access Points). (Webopedia, 2000)

E-mail – ISPs provide both incoming mailboxes and outgoing mail service through an e-mail server for transmission of Internet e-mail messages.

POP (Post Office Protocol) is usually used to retrieve e-mail from an e-mail server (IMAP, a newer protocol, can also be used). (Webopedia, 2000)

SMTP (Simple Mail Transfer Protocol) is usually used to send messages, although newer POP versions do not require it. (Webopedia, 2000)

E-mail address is used to send e-mail to the correct recipient. The format is aname@domain (for example rkulzick@stu.edu).

Domain name – "the unique name of a collection of computers connected to the Internet. The domain contains subdomains separated by a period ("dot"). The domain that is farthest to the right is the top level domain, and each domain to the left helps further define the domain …." (Laudon & Laudon, 2000, p. 294).

Top level domain – is the right-most portion of the URL. There are 192 active country codes (such as .es for Spain, .de for Germany, and .uk for United Kingdom) in addition to function codes (such as .com, .edu, .gov, .net, and .org) which are used in the United States. Each top level domain has a domain name server, and some have more than one, such as .com.

Internet addresses –

IP (Internet Protocol) is the address portion of the TCP/IP protocol that is used to route a packet to its destination over the Internet. It is composed of four sets of up to 3 numbers separated by a period (for example, 123.12.123.1).

URL (Uniform Resource Locator) is a "user-friendly" address for an Internet resource. Requires a domain server to interpret the URL into an IP address.

Web browser – "A software package that provides the user interface for accessing Internet, intranet, and extranet websites." (O’Brien, 2001, p. G-22)

Web Server – A computer that delivers (serves up) Web pages upon request from a browser. The web pages are stored on the web server or accessed by it through a network. Every Web server has a unique IP address and possibly a domain name. (Webopedia, 2000)

Firewall – "Hardware and software placed between an organization’s internal network and an external network to prevent outsiders from invading private networks." (Laudon & Laudon, 2000, p. 298). Firewalls can also be used to provide security between parts of an internal network.

References:

Copeland, Lee. (2000, March 20). Packet-switched vs. circuit-switched networks. ComputerWorld. p. 74.

Laudon, Kenneth C. and Laudon, Jane Price. (2000). Management information systems: Organization and technology in the networked enterprise. (6^th ed.). Upper Saddle River, NJ: Prentice Hall.

O’Brien, James A. (2001). Introduction to information systems: Essentials for the Internetworked E-business enterprise. New York: McGraw-Hill Irwin.