DNS (Domain Name System) is a hierarchical distributed naming system that translates human-readable domain names, such as google.com, into IP addresses, which are used to identify and locate devices on a network. DNS is used to make it easier for users to access resources on the internet by using memorable domain names instead of IP addresses.
The DNS system consists of a network of servers that store information about domain names and their corresponding IP addresses. When a user types a domain name into a web browser, the browser sends a request to a DNS resolver, which is responsible for finding the IP address associated with the domain name. The resolver then queries the DNS system, starting from the root domain servers and working its way down the hierarchy until it finds the authoritative DNS server for the requested domain. The authoritative server then responds with the IP address associated with the domain name, which is returned to the user’s web browser.
DNS also provides several other services, such as caching and load balancing. Caching is used to improve the performance of DNS lookups by storing previously resolved domain names and their associated IP addresses in memory. This allows subsequent requests for the same domain name to be resolved more quickly, as the information is already stored locally.
Load balancing is another important feature of DNS. DNS load balancing is used to distribute traffic across multiple servers to improve performance and ensure high availability. When a user requests a domain name that is associated with multiple IP addresses, the DNS system can respond with different IP addresses each time the domain name is queried. This allows the user’s request to be directed to different servers, spreading the load across multiple servers and reducing the risk of overloading any one server.
In summary, DNS is a critical component of the internet that enables users to access resources using memorable domain names instead of IP addresses. With its hierarchical distributed naming system, caching capabilities, and load balancing features, DNS provides a reliable and efficient way to manage and access resources on the internet.