What Is a Domain?
DNS is a hierarchic database. A good analog in computing is a tree data structure as used in programming. Similar to a tree data structure, DNS has a root node, edges, and leaf nodes. Because it's a database, it also has lookup keys and values found by these keys by traversing the tree structure.
If you examine a DNS name such as www.amazon.com, you'll see that all these parts are represented in the name. But first, it's important to realize that in reality the DNS name is www.amazon.com. (with the trailing period). The period is not normally typed, but it is there and is significant. It represents the root node of DNS. Just as in programming, you must know where the root node is because it cannot be found automatically. However, ...
Get Concise Guide to DNS and BIND, The now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
