Just like mail delivery in the US and other countries. Internet addresses are used to get us or our mail to a known destination. Different methods are used to achieve mail delivering. In the US we have crisscrossing streets with sequential numbering. In Japan they have nested districts where the numbers wander about seemingly at random.
There are no streets in Cyberspace, and no way to create a linear ordering. Instead addressing is like the Japanese model, with domains and subdomains. On the Net, however, we have Domain Name Servers (DNS) which keep track of all addresses, so that it is almost impossible to get lost except when one of the servers is down. Our DNS is seidata.com. Some other DNS names are cnet.com, indiana.edu, and whitehouse.gov.
Internet addressing comes down to domains, personal identifiers for E-mail, Web service prefixes, and directory/file naming.
Either continue on down the page or click on the specific type of addressing you need help with.
-- Domain names -- E-mail adresses
-- Web addresses -- Newsgroup names and
addresses --
A domain name specifies a site, or a particular computer at a site.
It can have several parts. In the U.S. the last indicates the
type of domain: .com for commercial, .edu for educational, .org for
organization, .net for network, .gov for government, .mil for military.
The commercial online services are all connected to the Internet, with domain
names such as aol.com and compuserve.com. In other parts of the world,
other abbreviations are used: .co for commercial or .ac for academic,
followed by a country code, such as .uk for the United Kingdom or .no for
Norway. There are nearly 300 country codes assigned by the ISO
(International Standards Organization).
There may be parts stuck on before the main name to signify a subdomain. In many cases, the subdomain indicates one of several computers at the same site. Thus, math.rutgers.edu is the math department server at Rutgers University in New Jersey.
Every domain name has a numeric equivalent, which people rarely have to use, but computers need in order to know how to route messages. Domain names can be registered for a fee with InterNIC, which assigns the numbers.
Take SEI Data's Support address
support@seidata.com. It consists of a personal or job identifier
(support) and a domain name (seidata.com) connect with the @ sign (read 'at').
Almost all Internet E-mail addresses have this general form, which
is designed to be reasonably readable for people. Computers, however,
work better with numbers, so internally a computer trying to send a message
converts the seidata.com domain name into a numeric equivalent.
The part before the @ sign is the personal identifier. It may be made up from the user's name or it may be quite arbitrary, as in the case of Compuserve's numeric identifiers. An example is 73314.722@compuserve.com for humorist Dave Barry. Some identifiers represent a position or function, such as postmaster @netcom.com at an Internet service, or sales@cdrom.com at an online store.
It is very important to enter the email address exactly as it is formed. Periods, underlines, plus marks, combinations of upper and lower case, and more can be found.
It is important that the Internet mail protocol allows users to append their real names to their address. In my case, that means that I can instruct my mail program to use the address marriage@seidata.com(Ron Marriage) starting with my Internet address and appending my name in parentheses. You will sometimes see it in the opposite order and using angle brackets to enclose the mail address. I could write Ron Marriage <marriage@seidata.com> instead of the other form.
World-Wide Web addresses are officially called Uniform Resource Locators
(URLs). They contain domain names, much like mail domain names, except
that most begin with the www. subdomain name. For example,
www.eng.ox.ac.uk is the Web server in the English
department of Oxford University, and www.census.gov
is the address of the U.S. Bureau of the Census Web server.
Web addresses always begin with a service type, most often http (hypertext transfer protocol, where hypertext means text with links). The service type is followed by a colon, then an address. Servers are indicated by two slashes and then the domain name. Thus SEI Data's homepage is http://www.seidata.com/.
After the domain name can come a sequence of directories and subdirectories, separated by slashes, often ending in a file name. The simplest directory name is /, a slash all by itself, indicating the root directory.
The address http://www.realaudio.com/products/player.html includes a domain name for the RealAudio Web server, the products directory, and the hypertext page file 'player.html'. This page contains the links to downloadable copies of the RealAudio software for receiving 'radio' broadcasts over the Net.
Newsgroup addresses are composed in the opposite order from mail and
server addresses, with the most general identifier first, followed by more
specific identifiers. For example, the recreation group is called
rec., and it has a division called
rec.games. Within that are specific
groups, such as
rec.games.go, and further
divisions with further groups, such as
rec.games.chess.analysis, where
people discuss the latest tournaments and matches.