A domain name is an identification string that defines a realm of administrative autonomy, authority or control within the Internet. Domain names are formed by the rules and procedures of the Domain Name System (DNS). Any name registered in the DNS is a domain name.
Domain Name definition by Wikipedia
Every website is located by a domain name or address, creating a form of phone book or address book for the Internet.
About the Word
A domain is created through a domain registrar, a company that registers the address of a site and links a name to that address. The address, the Internet Protocol (IP) resource identifier is actually a set of numbers, unique identifiers and namespaces, but for usability, words are used for website addresses. When you type in example.com, the browser taps into the IP addresses to locate the number or address of example.com, which might be
1234567 and directs the web browser, thus the user, to that location on the web on that specific server and that specific address. Continue reading WordPress Words: Domain