The rightmost extension of a web site is called the domain name. The Internet Assigned Numbers Authority (IANA) classifies domain names into three types: country code domain names, generic domain names, and special domain names for technical infrastructure purposes. There are about sixteen generic domain names available for use. They include .aero.biz.cat.com, coop.edu.gov.info.int.jobs.mil.mobi.museum.name.net.org.pro, and .travel.

Free domain names are generic domain names which can be used by anyone without any restrictions. Commonly available are .com.net.org.biz.info.name, and .pro. Generally, free domain names are operated under policies established by the global Internet community through ICANN (Internet Corporation for Assigned Names and Numbers). The other extensions have limited purposes and are created basing on specific policies formulated by communities that are directly connected with that domains services.

There are many Internet service providers in the market who offer services such as free domain name allocation, which includes choosing sub-domains, short URLs, URL redirection also known as domain forwarding or redirecting domain name to real website addresses, URL cloaking or masking used to mask a real website with the free domain name, path forwarding for both subdirectories and files, search engine optimization, banner-free, popup free web site development services with or without the www prefix, and dynamic IP support for those who wish to run a webserver from their home computer.

Free domain names offer many benefits for individuals and small organizations, such as low investment, quick establishment in the Internet market, and visibility to their clients or customers.