What is a dns lookup?

A Domain Name System (DNS) lookup is an essential part of the Internet, performing a vital role in how websites and other systems are located and identified on the Web. Simply put, a DNS lookup is a process for finding out which IP address is associated with a domain name. It's often referred to as "DNS resolution" and works by combining the power of both local name servers — those maintained by your Internet Service Provider (ISP) — and the central naming system that maps internet domains to IP addresses. Here's how it works in a nutshell:

When you link to any site on the web — say, https://www.example.com — your local DNS server doesn't have any knowledge of who owns that domain or what IP address it points to. So it turns to other DNS databases to get more information about where that domain is located and which IP address it points to.

The query then enters the hierarchy of DNS servers around the world — starting from root servers, then Top Level Domain (TLD) servers, then Authoritative Name Servers, until finally getting its response from the server that controls the requested domain. That data contains information such as MX records (mail server records), A records (IP address records), TXT records, and so on. That's roughly how DNS resolution works in layman's terms; but if you want more details on how this all works, our article What Is DNS? covers all of those topics in greater detail.

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