A domain name is a string of characters that identifies a realm of authority within a Domain Naming System (DNS).
A domain name is a string of characters that identifies a realm of authority within a Domain Naming System (DNS). They serve as human-friendly pointers to IP addresses and other resources that host various services like HTTP/HTTPS, SMTP, IMAP, SIP, etc. Domain names can be (and are) used on private networks, but they are an integral component of the modern Internet.