A record: Purpose & Details

The Domain Name System (DNS) is an interesting but hard (at the beginning) realm to access. Every detail within it matters and is the difference between being available on the Internet or not, working correctly or not. That is why understanding the A record’s purpose and details is very important.

What is a DNS record?

A DNS or Domain Name System record is a file containing specific instructions and information associated with a domain name. There are many DNS records, and they are stored in authoritative DNS servers. They all accomplish different purposes.

The structure of a DNS record includes a text file or files written in DNS syntax and have time-to-live (TTL). Simplifying, DNS syntax can be described as lines of characters written to command the DNS server to execute defined tasks.

The TTL is a value (time) defined by network administrators to establish the frequency for the record to be updated by the DNS server.

A record: Purpose

The “A” stands for address. The A record’s purpose is to point a domain name to its corresponding IP address.

The A record is vital in the DNS resolution process. It collaborates in the necessary translation from domain names (human language) to IP addresses (machine language) for domains to be loaded. In the past, without this translation, the Internet was not the most comfortable experience because users had to type IP addresses ( instead of easy domain names (domain.com). And currently, that translation is a must to access a domain. So, there is no way to skip the use of the A record.

Every time a user requests a domain, an immediate search for its IP address gets started. Once it is obtained, the domain gets accessible to the user. The A records actively participate in this process. Now you can imagine how needed the job of A records is all day, every single day!

A record: Details

The A records point exclusively to IPv4 addresses. Yes, IP addresses latest version is IPv6 but to point those, you have to use a different DNS record (AAAA).

Suggested article: IPv4 vs IPv6 – What is the difference?

The structure of IPv4 addresses is a 32-bit number. It will be easy to identify an IPv4 address because it will be written in decimal digits, distributed in four groups (8-bit fields) separated by periods (.). Every 8-bit field means a byte. What you have in the end is something like this:

Remember, an A record can store only a 32-bit IPv4 address.

The A records are still very used, no matter the availability of IPv4, is a big issue since the early 1990s. At that time, the Internet growth exceeded all expectations, just like the number of machines requesting connection. This led to a shortage of IPv4 and a need for a new version. IPv6 has been ready since 1999, but the transition is not yet completed.

How to check DNS A record?

  1. Open Command Prompt or Terminal: For Windows, use Command Prompt. For macOS or Linux, use Terminal.
  2. Using nslookup:
    • Type nslookup followed by the domain name you want to check, such as nslookup example.com.
    • The output will display the A Record, showing the IP address the domain is pointing to.
  3. Using dig (mainly for macOS/Linux):
    • Type dig followed by the domain name, like dig example.com.
    • By default, dig returns the A Record. The answer section of the output will provide the domain’s IP address.
  4. Analyzing the Output: Both commands will show you the IP address associated with the domain name, known as the A Record.
  5. Alternative Online Tools: If you prefer a graphical interface, numerous online DNS lookup tools are available.


Now you know A record’s purpose and details. It is an essential DNS record you better should learn how to use!