When you type a website like example.com, your computer needs to find out where that website actually lives. DNS is the system that answers that question.
Most DNS issues are not caused by incorrect settings, but by misunderstanding how this lookup process works. This article explains that process in simple terms so you can understand what is happening and why results may differ.
What DNS Does in Simple Terms
DNS is like a directory. You ask for a name, and it gives you an answer.
For example, when you enter example.com, DNS returns information such as an IP address, which tells your system where to connect.
DNS does not load the website. It only tells your system where to go next.
What Actually Happens When You Look Up a Website
The request does not go straight to UltraDNS. It goes through several steps.
First, your device makes the request. This could be your laptop, phone, or a server. This is called the source.
Before leaving your network, the request may be answered locally. Your device, browser, router, or company network may already have a saved answer from earlier. If they do, they use that instead of asking again.
If there is no saved answer, the request is sent to a system that performs lookups for you. This is called a recursive resolver. It is usually provided by your ISP or company network.
The resolver checks if it already knows the answer. If it does, it returns that saved result.
If it does not, it asks the authoritative DNS. For domains hosted on UltraDNS, UltraDNS is the authoritative source and holds the official answer.
UltraDNS returns the configured answer. The resolver saves that answer for a period of time and sends it back to your device.
Your system then tries to connect to that destination. At this point, DNS is finished.
Why Two People Can See Different Results
Not everyone gets the same answer at the same time.
- Different networks use different resolvers
- Resolvers may have saved different answers at different times
- Company networks may override public DNS
- VPNs and security tools can change results
Because of this, one person may see a problem while another does not.
Why Support Asks You to Test from the Affected Device
DNS depends on where the request comes from. Testing from a different computer or network may not show the same result.
This is why support asks for testing from the affected device, so the exact resolution path can be analyzed.
What a Zone and Record Mean
A zone is where your DNS settings live. For example, example.com is a zone.
A record is a rule inside that zone that defines how a hostname resolves.
- A record points to an IP address
- A CNAME points to another name
- An MX record controls mail routing
- A TXT record stores verification or policy data
What a Subdomain Means
A subdomain is anything added before your main domain, such as app.example.com.
It can exist inside your main DNS zone or as a separate delegated zone. These are different configurations and behave differently.
What DNS Does Not Do
DNS only tells systems where to go. It does not:
- Host your website
- Create files or directories
- Control browser behavior
- Manage HTTPS or certificates
If a website does not load but DNS is correct, the issue is likely outside DNS.
Why DNS Changes Are Not Immediate
DNS answers are saved by systems along the way. This is called caching.
Even after you update DNS, some systems may continue using older results until those saved answers expire.
Practical Takeaway
- DNS tells systems where to go, not what happens after
- The correct answer may exist even if some users see different results
- Caching is the main reason for delays
- Different users can see different results at the same time
- Testing must be done from the affected device