General Computer Science 320201 GenCS I & II Lecture ... - Kwarc

Domain names must be registered to ensure uniqueness
(registration fees vary, cybersquatting)
Definition 511 ICANN is a non-profit organization was established to regulate humanfriendly
domain names. It approves top-level domains, and corresponding domain name registrars
and delegates the actual registration to them.
c○: Michael Kohlhase 347
Let us have a look at a selection of the top-level domains in use today.
Domain Name Top-Level Domains
.com (“commercial”) is a generic top-level domain. It was one of the original top-level
domains, and has grown to be the largest in use.
.org (“organization”) is a generic top-level domain, and is mostly associated with non-profit
organizations. It is also used in the charitable field, and used by the open-source movement.
Government sites and Political parties in the US have domain names ending in .org
.net (“network”) is a generic top-level domain and is one of the original top-level domains.
Initially intended to be used only for network providers (such as Internet service providers).
It is still popular with network operators, it is often treated as a second .com. It is currently
the third most popular top-level domain.
.edu (“education”) is the generic top-level domain for educational institutions, primarily
those in the United States. One of the first top-level domains, .edu was originally intended
for educational institutions anywhere in the world. Only post-secondary institutions that are
accredited by an agency on the U.S. Department of Education’s list of nationally recognized
accrediting agencies are eligible to apply for a .edu domain.
.info (“information”) is a generic top-level domain intended for informative website’s, although
its use is not restricted. It is an unrestricted domain, meaning that anyone can obtain
a second-level domain under .info. The .info was one of many extension(s) that was meant
to take the pressure off the overcrowded .com domain.
.gov (“government”) a generic top-level domain used by government entities in the United
States. Other countries typically use a second-level domain for this purpose, e.g., .gov.uk
for the United Kingdom. Since the United States controls the .gov Top Level Domain, it
would be impossible for another country to create a domain ending in .gov.
.biz (“business”) the name is a phonetic spelling of the first syllable of “business”. A
generic top-level domain to be used by businesses. It was created due to the demand for
good domain names available in the .com top-level domain, and to provide an alternative to
businesses whose preferred .com domain name which had already been registered by another.
.xxx (“porn”) the name is a play on the verdict “X-rated” for movies. A generic top-level
domain to be used for sexually explicit material. It was created in 2011 in the hope to move
sexually explicit material from the “normal web”. But there is no mandate for porn to be
restricted to the .xxx domain, this would be difficult due to problems of definition, different
jurisdictions, and free speech issues.
c○: Michael Kohlhase 348
Note: Anybody can register a domain name from a registrar against a small yearly fee. Domain
names are given out on a first-come-first-serve basis by the domain name registrars, which usually
also offer services like domain name parking, DNS management, URL forwarding, etc.
The next application-level service is the SMTP protocol used for sending e-mail. It is based on
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