Internet Addresses
The Internet is uses three types pf addresses for communications: (1) e-mail addresses, (2) Web site URL addresses, and (3) Internet protocol (IP) addresses of individual computers attached to network.
E-mail-Address. The format for an e-mail address is USER NAME@DOMAIN NAME. For example, the address of the author of this textbook is jah0@lenigh.edu. There are no spaces between any of the words. The user name (or in this case, the user identification [ID]) is jah0). A domain name is an organization’s unique name combined with a top-level domain (TLD) name. In the previous example above, the unique name is Lehigh and TLD is edu. Following are examples of TLD names:
.com commercial
.net network provider
.org nonprofit organization
.edu education and research
.gov government
.mil military agency
.int international intergovernmental
Outside of the United States, the TLD names consist of the country code, such as .uk for the United Kingdom and .es for Spain. The Internet Ad Hoc Committee (IAHC) has introduced a category called a generic top-level domain (gTLD), which includes the following:
.firm a business
.store goods for sale
.wed WWW activities
.arts culture/entertainment
.rec recreation entertainment
.info information service
.nom individual/personal
The Internet e-mail addressing system allows the user to send e-mail directly to the mail-boxes of users of all major online services, such as America Online and CompuServe.
URL Address. The URL is the address that defines the path to a facility or file on the Wed. URLs are typed into the browser to access Web site home pages and individual Web pages and can be embedded in Web pages to provide hypertext links to other pages. The general format for a URL is protocol prefix, domain name, subdirectory name, and document name. The entire URL is not always needed. For example, to access the South-Western Publishing home page, only the following protocol and domain name are required:
http//:www.academiv.cengage.com
The protocol prefix is http//: and the domain name is www. academiv.cengage.com From this home page, the user can activate hyperlinks to other pages as desired. The user can go directly to a linked page by providing the complete address and separating the address components with slashes. For example,
http//:www.academiv.cengage.com/accounting/hall
subdirectories can be several levels deep. To reference them, each must be separated with Subdirectories a slash. For example, the elements of the following URL for a hypothetical sporting goods company are described below next.