Domain name is the address of specific business, organization, person, network, etc on the internet.
This name helps individuals to reach the available data about anything easily instead of using long ip address.
A fully qualified domain name (FQDN) is a domain name that is completely specified with all labels in the hierarchy of the Domain Name System (DNS), having no parts omitted.
The domain name has many levels, The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, info, net, edu, and org, and the country code top-level domains (ccTLDs).
Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites.