A domain name is a unique name that identifies a website. Each website has a domain name that serves as an address, which is used to access the website by its users. Whenever you visit a website, the domain name appears in the address bar of the web browser. It is an identification string that defines a realm of administrative autonomy, authority or control on the Internet. Domain names are formed by the rules Domain Name System (DNS). Any name registered in the DNS is a domain name.