What is DNS and how does the domain name resolution process work?

The Domain Name System, or DNS, is a distributed database that translates human-readable text domain names into the numerical IP addresses required by computers to communicate with each other. When you enter a website address in a browser, your computer does not know which server holds this resource, so it contacts the DNS system.

The name resolution process starts with the local cache of your computer and operating system. If the record is not there, the request is sent to your internet service provider's resolver or a public DNS server, such as Cloudflare or Google. The resolver sequentially queries the root servers, then the top-level domain root zone servers, and finally, the authoritative server for the specific domain.

The obtained IP address is stored in the cache for a specific period determined by the TTL value. This avoids repeated long requests during subsequent visits to the same resource. Understanding how DNS works is critical for developers when configuring web servers, debugging website availability, and managing mail records.