Center for Problem-Oriented Policing

Appendix A: Key Terms and Concepts

The Internet is a global network comprising millions of smaller networks and individual computers connected by cable, telephone lines, or satellite links. The Internet permits individuals to connect with other computers around the world from the privacy of their own homes. Although the terms Internet and the World Wide Web (WWW) are often used interchangeably, the web specifically refers to the worldwide collection of electronic documents and other files stored throughout the Internet (on web pages and in websites). The web accounts for 90 percent of Internet usage.[91]The web allows individuals to search for and download text, graphics, audio, and video on topics of interest from around the world. They can also upload their own electronic files for others to access. In addition to the World Wide Web, the Internet enables a number of other services and forms of communication, including e-mail, mailing lists, e-groups, newsgroups, bulletin boards, chat rooms, instant messaging, and peer-to-peer (P2P) networks. These services permit a user to engage in conversations with other individuals and share electronic files. Specific terms associated with the Internet, the World Wide Web, and related communication services are in the following table:

Table 3: Key terms and concepts associated with the Internet, World Wide Web, and related communication services
The Internet
TermDefinition [92]
HostAny computer or network connected to the Internet.
ModemDevice for connecting a host to the Internet. Includes dial-up modems that may use standard telephone lines and dedicated cable modems.
Internet Protocol (IP) addressA number that uniquely identifies each host using the Internet.
ServerA computer configured to provide a service to other computers in a network, including access to hardware and software and centralized data storage. Different servers may be used to perform specific functions (e.g., web server or e-mail server).
Internet Service Provider (ISP)A business that provides individuals or companies access to the Internet (e.g., AOL, MSM, Earthlink). ISPs use authentication servers to verify customers' passwords.
File Transfer Protocol (FTP)A protocol that permits the downloading and uploading of electronic files. Downloading is the process by which a computer receives an electronic file from the Internet via an FTP server; uploading is the process of transferring electronic files from a computer to an FTP server on the Internet.
The World Wide Web
TermDefinition [93]
Web pageAn electronic document that may comprise text, graphics, audio, and video, as well as links to other pages.
WebsiteA collection of related web pages and associated media stored on a web server.
Home pageFirst page displayed on a website that usually acts as an introduction to the site.
Web camVideo camera that permits live images to be displayed via a web page.
Universal Resource Locater (URL)A web page's unique location or address.
Web browserSoftware that allows web pages to be accessed and viewed (e.g., Internet Explorer, Netscape, Mozilla Firefox).
HyperlinkA link provided within a web page to connect other related web pages. Pop-up links not requested by the user may also appear on some web pages.
Search engineA program (e.g., Google, Alta Vista) that locates websites and web pages using key words.
Communication Services
TermDefinition [94]
E-mailA method of communication between individuals connected to the Internet involving the transmission of text messages and attached files.
Mailing listsA group of e-mail addresses given a common name so all members on the list receive the same message. There is a central list owner who controls who is on the list and what material can be sent. Individuals may subscribe to have their name and address added to the mailing list.
E-groupsGroups established to share information on a topic of common interest. Potential members need to subscribe to the group. In addition to e-mail, an e-group may offer other features such as a chat room, a bulletin board, and a central home page.
NewsgroupsA site, stored on a news server, that allows contributors to have discussions about a particular subject by posting text, pictures, etc., and responding to previous posts. In most cases no one owns a newsgroup and there is no central authority. However, in some cases a password may be required, and some newsgroups filter posts through a moderator. The network of newsgroups is called Usenet.
Bulletin Board Systems (BBS)Bulletin board systems, which predate the Internet, are similar to newsgroups, but tend to be in real time to allow contributors to engage in conversations. Bulletin boards are often hosted by an owner rather than a server, and may be accessed directly via a modem without going through the Internet.
Chat roomsA chat room is a location on a server that permits multiple users to engage in real-time conversations and exchange electronic files. Many chat rooms are open to anyone to log into, but some are closed. They may employ a moderator, but users can nominate a pseudonym.
Instant messaging (IM)Similar to chat rooms, but instant messaging permits private conversations with nominated contacts. Once a connection is established, direct contact between users is possible without the need for a central server.
Peer-to-peer (P2P)A network in which each computer is an equal partner and all work cooperatively together. All computers in the network have a common file-sharing program (e.g., KaZaA, Morpheus, Limewire), allowing users to connect directly to each other's hard drive to search for and exchange files.

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