Domain Name Space:
Domain name space was designed to achieve hierarchical name space. In this, the names are represented as a tree like structure with root element on the top and this tree can have a maximum of 128 levels starting from root element taking the level 0 to level 127.
This diagram represent the domain name space where the root element is present at the top most level i.e., level 0. The root element always represents the NULL string (empty, string). The next level to the root element is node (children of root element). Each node in the tree has a label and a domain name.
Label:
1. It is a string which can have maximum of 63 characters.
2. Each node in that level should have different labels thereby assuring the individuality of the domain name.
3. In other words, Labels are the names given to domains.
4. Domain is a sub tree in domain name space tree structure. The domain can be further divided into sub domains.
Domain name:
It is the sequence of labels. In domain name the sequence of labels are separated by dot (.).
