Key Topics
The Internet is a worldwide system of computer networks in which users at any one computer can extract information from any other computer. It is a public, cooperative, and self-sustaining facility accessible to hundreds of millions of people worldwide. The World Wide Web (also referred to as WWW or the Web) is an Internet facility that links documents locally and remotely. The Web document, or Web page, contains text, graphics, animations, and videos, as well as hypertext links. The links in the page let users jump from page to page (hypertext), whether the pages are stored on the same server or on servers around the world. Web pages are accessed and read via a Web browser, the two most popular being Internet Explorer and Netscape Navigator. Although there are other facilities on the Internet (e.g., file transfer protocol, newsgroups, chat rooms), generally speaking, when people refer to the Internet, they are referring to the WWW.
The following are some common Internet terms you should know.
The following explains the parts of the URL using the DON Information Management/Information Technology Web site as an example:
- http defines which Internet Protocol to use. If you are typing in a World Wide Web site, you normally do not have to type the http; browsers use it by default.
- www indicates that the page is found on the World Wide Web
- www.doncio.navy.mil indicates the Web site’s home page. Further delineation of the URL indicates a specific document or page on the Web site. For example, the URL to go directly to the knowledge sharing area of the DON IM/IT Web site is:
http://www.doncio.navy.mil/interestTemplate.asp?theID=4&type=category
The .mil extension indicates the type of Web site. The following extensions have traditionally been used:
Extension Meaning .com commercial .edu educational .gov government .mil military .net network .org organization .uk, .fi, .jp, etc. country
There are several types of search tools that can be used to search the Internet. These tools are used to find information on the Internet when you don’t know the URL. There are currently more than 16,000 search engines and/or directories. The following Web sites maintain lists of search engines and directories:
Search EnginesSearch engines search the Web based on criteria you enter. Typically, a search engine works by sending out a “spider” to fetch as many documents as possible. A spider is a program that automatically fetches Web pages and feeds them to the search engine. It’s called a spider because it “crawls” over the Web. Another program, called an indexer, then reads these documents and creates an index based on the words contained in each document. Each search engine uses a proprietary algorithm to create its indices such that, ideally, only meaningful results are returned for each query. Some of the more popular search engines are:
Meta search engines use a single interface to provide simultaneous searching of the most popular search engines. Some popular metasearch engines are:
DirectoriesA directory is a search site that catalogs Web sites by subject and also manually indexes the site, providing a brief description of its content. Popular directory sites are:
Virtual libraries are directories that librarians or cybrarians have organized in a logical way. Some virtual library sites are:
For more information on Searching, go to Searching Resources for broad based search information, or for more topic specific searching.
“Internet bulletin boards” is a collective term for an Internet service that permits one person to post a message and for others to read and comment (post a reply). Uses include:
Two popular bulletin board systems on the Internet are:
DOD Hyperlink Disclaimer: The appearance of hyperlinks does not constitute endorsements by the Department of the Navy of the website or the information, products or services contained therein. For other than authorized activities such as military exchanges and Morale, Welfare, and recreational sites, the Department of the Navy does not exercise any editorial control over the information you may find in these locations. Such links are provided consistent with the stated purpose of this CD-ROM. |