DNS, or Domain Name System, is the backbone of the internet and serves as a critical component of how users access websites and other online resources. At its core, DNS is a system that translates human-readable domain names into the IP addresses that computers use to communicate with one another over the internet.
There are several key concepts to understand when it comes to DNS:
Domain Names: Domain names are the human-readable names that people use to access websites and other online resources. Examples of domain names include google.com, facebook.com, and wikipedia.org.
IP Addresses: IP addresses are the numerical addresses that computers use to identify one another over the internet. Every device that connects to the internet has an IP address that is used to route traffic between devices.
DNS Servers: DNS servers are the computers that perform the translation of domain names into IP addresses. DNS servers are responsible for storing and serving DNS records, which contain information about which IP address is associated with a given domain name.
DNS Records: DNS records are the individual pieces of data that make up the DNS system. DNS records can include information about which IP address is associated with a given domain name, as well as other metadata about the domain, such as its time-to-live (TTL) value.
The way that the DNS system works is fairly straightforward. When a user enters a domain name into their web browser, the browser sends a DNS query to a DNS server asking for the IP address associated with the domain name. The DNS server responds with the IP address, which the browser then uses to connect to the server hosting the website or resource.
This process is facilitated by a series of hierarchical DNS servers, with the top-level servers containing information about the root domain (.), and lower-level servers containing information about specific top-level domains (such as .com, .org, etc.) and individual domains within those top-level domains.
In summary, DNS is a critical component of how the internet works, allowing users to access websites and other online resources using human-readable domain names instead of numerical IP addresses. DNS works by using a hierarchical system of DNS servers to translate domain names into IP addresses, enabling devices to communicate with one another over the internet.