The domain name is made from various alpha-numeric characters and the special character. There are various domain names exist, top level domain name is on the right side of the dot, while the second level domain is on the left side of the dot. The other type is sub domain. It is left side of the second-level domain before dot.
The second-level domain is the readable part of the domain name. The registrant defines the second-level domain. It typically refers to the organization or entity associated with the IP address.