Domain Name System (DNS) is a protocol that allows us to use human readable names to communicate over networks, rather than having to manage and memorize IP addresses.
The Domain Name System (DNS) is a core network service that allows devices to communicate much like we do on our smart phones. Generally we don’t memorize phone numbers any more, we just save them under names in our Contacts app.
DNS works the same way, where we assign an IP address to a name. If a device doesn’t know the IP address or name of a device with which it needs to communicate, it will find that information from DNS servers either on the local network or on the Internet.
The primary identifier of a network device is the IP address. Due to the limited number of IP addresses available, IP assignments are temporary and cumbersome for users. DNS offers a higher-level, more permanent abstraction for the network and better usability for its users.
With DNS, users can use the network even if its components are changed with their IP addresses reassigned. For example, menandmice.com will always be menandmice.com even if it’s connected network device (the webserver) is moved or reconfigured.
More advanced use cases for DNS include sophisticated routing for constantly shifting networks. For example, managing the high-speed mobile internet connections of 5G or delivering content such as media or gaming faster by routing the user's request to the network edge and geographically closer to the endpoint.
DNS is a hierarchical and distributed system designed to reflect administrative responsibility.
At the highest level of authority, 13 root name servers store information about the numerous Top Level Domain (TLD) name servers, which can be queried for details about the innumerable DNS name servers.
To ensure uninterrupted operation and distribute workloads, DNS servers are often configured in primary/secondary relationships. The primary server is synchronized to a number of secondary servers for redundancy. Changes are made to the primary server and propagated to the secondaries.
Usually run by an ISP, these servers do the majority of the work. While companies may have their own, many times people will point to Google, for example, at 220.127.116.11 or 18.104.22.168
name servers in the domain at the highest level in the hierarchical DNS. For example, in the domain name menandmice.com, .com would be the Top Level Domain. These servers may also direct the recursive server to the proper authoritative servers.
Name servers for the root zone that may contain the information necessary to find the aligning IP for a DNS record or may direct you to the Top Level Domain Servers.
The last place a recursive server will check for a domain name and corresponding IP. When new DNS records are created they must be submitted to an authoritative server responsible for that domain.