Domain Name System (DNS) maps domain names to IP addresses from "summary" of Data Communications and Networking by Behrouz A. Forouzan
The Domain Name System (DNS) is a crucial component of the Internet that plays a key role in translating human-readable domain names into machine-readable IP addresses. This translation is essential for enabling communication between devices on a network. When a user enters a domain name into a web browser, the DNS is responsible for mapping that domain name to the corresponding IP address of the server hosting the website. This process allows the user's device to establish a connection with the server and retrieve the desired web content. The DNS operates through a distributed database system that stores information about domain names and their associated IP addresses. This database is distributed across multiple servers known as DNS servers, which work together to efficiently resolve domain name queries. When a user's device requests the IP address of a particular domain name, the DNS server responsible for that domain name is queried. If the server has the corresponding IP address information cached, it can quickly provide the answer. However, if the information is not cached, the server may need to query other DNS servers in the hierarchy to obtain the desired IP address. The hierarchical structure of the DNS plays a crucial role in ensuring efficient and reliable domain name resolution. The DNS hierarchy consists of multiple levels, including the root level, top-level domains (TLDs), second-level domains, and subdomains. Each level in the hierarchy is responsible for managing a specific set of domain names and their corresponding IP addresses.- The Domain Name System is a fundamental component of the Internet that enables seamless communication between devices by mapping human-readable domain names to machine-readable IP addresses. Its distributed database system and hierarchical structure play a key role in ensuring efficient and reliable domain name resolution across the Internet.
