What is a domain name?
A domain name is a way to identify and locate computers connected to the Internet. A domain name must be unique; no two organizations on the Internet can have the same domain name. A typical domain name consists of a second-level domain and a top-level domain, such as "bigco.com". In addition, hostname and subdomain information can be added, for example: "tiger.newyork.bigco.com". The top-level domain name describes the type of organization or the country with the domain name (EDU, COM, GOV, UK, etc.).
Each domain name corresponds to numeric IP addresses which is used by the Internet to
transmit data. The Domain Name System completes the task of matching domain names to IP
addresses so that users of the Internet only have to remember domain names, not numbers.