The definition of a domain extension is the notation at the end of a web address that specifies an Internet category or a country code.
(noun)
- An example of a domain extension which is an Internet category is .com for commercial, .org for organization, .gov for government, .edu for all educational institutions, .mil for military or .net for a network.
- An example of a domain extension which is a country code is .us, .uk or .de.