It refers to the address that can be used to find computers connected on the network through IPs as it is difficult to remember the string of numbers. The names are designed in the manner to create a combination of numbers and letters, and it can be a grouping of extensions .net, .com, etc., that is allocated for a time period.
All the information is stored in a tree-like structure where the system maintains the resolution mechanism and the corresponding value. It must be registered by the web development team and must be unique.