Library at UCC: Citation & Style Guides: URL Domain Names

The Domain Name System acts like a phone book for the Internet by translating IP addresses into user-friendly computer hostnames, or domain names, which are the suffixes found at the end of website URLs.

Domain Suffix
.com	Commercial Represents the word "commercial," and is the most widely used extension in the world.
.net	Network Was originally intended for sites related to the Internet, but now used for a variety of sites.
.org	Organization Originally intended for non-commercial "organizations", but now used for a wide variety of sites.
.edu	Educational Used for educational institutions like universities and colleges.
.biz	Business Used for business sites, usually small businesses.
.gov	Government Used for U.S. Government sites, formerly only federal government but later expanded to state and local.
.mil	Military Used for U.S. Military sites, including army, navy, air force, etc.
.int	Intergovernmental Used for registering organisations established by international treaties between or among national governments.