Just like the A is the first letter you learn from the alphabet, the A record will be the first DNS record you learn from the DNS. It is one of the first records that you create after creating a DNS zone, and it has a fundamental purpose. Do you want to know what it is?
What is the A record?
The A record is a DNS record that we can’t live without. Or at least the Internet won’t be possible the way we know it.
The A comes from the word address, which in this case is an IPv4 address (32-bit address). The A record is a DNS record that point to the IP address of a domain name (hostname).
When you write a domain name into your address bar, the device will search for exactly this record, so you can access the content.
No matter the control panel for managing your DNS, when you open an A record, you will see:
Host/Domain name: The name of your domain, like yourcompany.com.
Type: Here, it will show the type of the record, in this case, A.
Points to: The IPv4 address to where the record is pointing. Example 18.104.22.168.
TTL. The period this record is valid before it needs to be revisited. It can be 3600 or another value in seconds.
You can have more than one A record for the same domain. You can use it for load balancing if you have multiple servers or if you want to direct traffic based on criteria like geolocation or another.
Why is the A record important?
Without A records, we (people) wouldn’t be able to access websites based on their names. We would need to remember all the IP addresses for each site, just like we used to remember the phone numbers in the past. And you can imagine how hard this could be because today, we use not a single site per day but hundreds.
When you are accessing any site on the web, you will need to know where they are located. Therefore, your browser or application needs to read the A record and find the IPv4 corresponding to the hostname you input.
Your device can find it out by performing a DNS query to the hostname for the A record.
When it finds it and reads it, your device will be able to open the site. It will also save the information about the domain name based on the time that the TTL inside the A records indicates. The next time you want to visit the site, the device will first check if the A record is still inside its DNS cache. You can directly access the site without a new DNS query if this is the case.
The A records are the essence of the DNS. They link domain names to their IPv4 addresses. Without them, the use of the Internet will be incredibly difficult and slow. Thanks to them, we can enjoy all the benefits of a fast and agile Internet.