Have you ever registered a domain name, launched a website or changed your hosting provider, only to discover that your website is not loading as expected? The problem may be related to DNS.
DNS, short for Domain Name System, is one of the essential technologies that makes the internet easy to use. It allows people to visit websites using memorable domain names instead of having to remember numerical IP addresses.
For businesses, DNS is more than a technical detail. It helps direct visitors to websites, routes business emails to the correct servers and supports the services that keep an organisation connected online.
Understanding DNS can help you troubleshoot website problems, manage domain names more confidently and avoid mistakes when changing hosting providers or email services.
In this guide, we explain what DNS is, how it works, the most common DNS records, what DNS propagation means and how DNS relates to website hosting and cybersecurity.
What Is DNS?
The Domain Name System (DNS) is a distributed system that translates human-readable domain names into information that computers use to locate internet services.
For example, when someone types example.com into a browser, the browser needs to discover which server or network endpoint should handle that request. DNS helps provide the necessary information.
You can think of DNS as the internet’s address directory. People remember names, while computers use network addresses and other technical information to communicate.
Without DNS, users would have to rely much more heavily on IP addresses to access online services. Managing websites, email systems and other internet-connected services would be considerably less convenient.
DNS is used for much more than websites. It can also help direct email, verify domain ownership, support security policies and identify services associated with a domain.
How Does DNS Work?
When you visit a website, several steps may occur before the page appears on your screen. Cached DNS information can shorten this process, but a typical lookup works as follows.
Step 1: You Enter a Domain Name
Imagine that you want to visit a business website. You enter its domain name into your browser.
Your device first checks whether it already has usable DNS information stored locally. If it does, it may be able to use that information without performing a new lookup.
Step 2: A DNS Resolver Looks for the Answer
If the necessary information is not available in the local cache, your device asks a DNS resolver, often provided by your internet service provider or another DNS service.
The resolver checks its own cache. If it already has a valid answer, it can return it immediately.
If not, it may need to query other DNS servers to discover the information required.
Step 3: DNS Servers Help Locate the Domain Information
For a typical uncached lookup, the resolver may contact a root DNS server to find the appropriate top-level domain servers. It can then contact the relevant top-level domain servers, such as those responsible for .com, before reaching the authoritative DNS servers for the domain.
The authoritative DNS servers contain the DNS records that define how the domain is configured.
For example, an authoritative record might identify the IPv4 address associated with a website’s hostname.
The resolver retrieves the necessary answer and returns it to the device.
Step 4: Your Browser Connects to the Website
Once the browser has the required network information, it can attempt to connect to the destination server.
The browser and server then communicate using the relevant web protocols. If the website uses HTTPS, they establish a secure TLS connection as part of that process.
The website’s content can then load, assuming the server, network and application are functioning correctly.
DNS does not normally store your website’s pages or deliver the actual website content. It helps your device discover where to connect.
What Are DNS Records?
DNS records are instructions and information stored within a domain’s DNS configuration. Different record types perform different functions.
Understanding the most common records is useful when connecting a domain to hosting, configuring business email or verifying a service.
A Record
An A record maps a hostname to an IPv4 address.
For example, a website’s root domain may have an A record pointing to the IPv4 address of its web server.
When a visitor looks up the domain, the record helps the browser discover the server’s address.
If you move your website to a different server, you may need to update the A record, depending on how your DNS and hosting are configured.
AAAA Record
An AAAA record maps a hostname to an IPv6 address.
IPv6 is the newer generation of internet addressing, designed to support a much larger address space than IPv4.
A website may use A records, AAAA records or both. The records should point to destinations that are actually configured to serve the relevant traffic.
An incorrect AAAA record can cause connectivity problems for some visitors even when the IPv4 configuration appears to work.
CNAME Record
A CNAME record makes one hostname an alias of another hostname.
For example, www.example.com might be configured as an alias of example.com, depending on the DNS provider and the rest of the configuration.
A CNAME does not directly contain an IP address. Instead, it identifies another hostname whose DNS information can be resolved.
CNAME records have specific restrictions, especially at a zone’s root or apex. Some DNS providers offer special flattening features to support configurations that would otherwise be unsuitable for a conventional CNAME.
MX Record
An MX record specifies the mail servers responsible for receiving email for a domain.
If your company uses addresses such as [email protected] or [email protected], the domain’s MX records help sending mail systems determine where messages should be delivered.
Incorrect MX records can interrupt incoming business email even when the website itself continues to work.
If you are configuring company email, review Tremhost’s business email hosting and follow the DNS instructions provided for the specific service you use.
TXT Record
A TXT record stores text associated with a domain. It is commonly used for domain verification and email security configurations.
For example, businesses may use TXT records to publish SPF policies, support DKIM configurations or publish DMARC policies through the relevant DNS record names.
Other services may also request TXT records to verify that you control a domain.
When adding these records, use the exact hostname and value provided by the service. A small formatting mistake can prevent verification or weaken an email authentication setup.
NS Record
NS records identify the authoritative name servers for a DNS zone.
When you register a domain, your registrar or DNS provider typically allows you to specify which name servers are responsible for managing its DNS records.
Changing name servers can change where the authoritative DNS configuration is managed. This is different from simply changing a website’s A record.
Before changing name servers, make sure the replacement DNS zone contains all the necessary records, including website, email and verification records.
SRV Record
An SRV record identifies the hostname and port for certain services, often alongside priority and weighting information.
Some communication platforms and specialised applications use SRV records to locate the services they need.
Most basic website owners will not need to modify SRV records regularly, but they can be important when configuring particular business applications.
DNS vs Domain Names vs Web Hosting: What Is the Difference?
These three concepts are related, but they serve different purposes.
A domain name is the memorable address people use to reach an online service, such as example.com.
DNS provides the records that help direct requests for that domain to the appropriate servers and services.
Web hosting provides the infrastructure and environment that stores, processes or serves the website’s content and applications.
Consider a company launching a new website. It registers a domain name, purchases a hosting plan and configures DNS so that visitors can reach the website on the hosting platform.
If the company changes hosting providers, it may need to update its DNS records. Its domain registration does not necessarily need to change, and its email service does not necessarily need to move.
This distinction is important because changing the wrong component can interrupt services that were working correctly.
If you are planning to launch a website, explore Tremhost’s shared hosting plans and choose a hosting environment that suits your website’s requirements.
What Is DNS Propagation?
DNS propagation is the term commonly used to describe the period during which DNS changes become visible to different resolvers and users.
Suppose you change a website’s DNS record to point to a new server. Some visitors may start reaching the new server while others continue using previously cached information.
This happens because DNS resolvers cache answers for specified periods. The Time to Live, or TTL, value influences how long a record may remain cached before a resolver needs to refresh it.
There is no single universal propagation time that applies to every DNS change. The timing depends on factors such as previous cache values, resolver behaviour, the nature of the change and whether the new DNS configuration is correct.
Changing the authoritative name servers introduces additional considerations because delegation and cached information can also affect the result.
If your website does not load immediately after a DNS change, avoid repeatedly editing records without understanding the problem. Each unnecessary change can introduce new errors and make troubleshooting more difficult.
First, confirm that the intended records are correct, the authoritative DNS servers are serving the expected zone and the destination server is ready to receive traffic.
Why Is My Website Not Working After a DNS Change?
DNS errors can have several causes. The important step is to identify which part of the connection is failing.
Incorrect A or AAAA Records
If the website’s address records point to the wrong server, visitors may reach an old server, an unrelated destination or a server that cannot serve the website.
Check the intended IP addresses against the instructions provided by your hosting company.
If both A and AAAA records exist, verify that both are correct and that the destination supports the relevant connections.
Incorrect Name Servers
If your domain uses the wrong authoritative name servers, the DNS records you edited may not be the records that the public internet is using.
Check the domain’s current name-server delegation and confirm where its active DNS zone is managed.
Missing DNS Records
A website migration or name-server change may leave important records behind.
For example, the website may work while business email stops receiving messages because the new DNS zone does not contain the required MX records.
Before a migration, inventory all records used by your website, email, verification services and other applications.
DNS Cache Issues
Your device or DNS resolver may still be using a cached answer.
You can compare results using different trusted DNS resolvers or devices, but remember that different results can also indicate inconsistent authoritative DNS configuration.
Clearing your local DNS cache may help with a local caching issue, but it will not repair incorrect authoritative records.
Hosting or Server Problems
Sometimes DNS is working correctly, but the destination server is unavailable or misconfigured.
The domain may resolve to the correct IP address while the website still fails because the web server is offline, a firewall is blocking connections, the virtual host is incorrectly configured or the application has an error.
This is why troubleshooting should not stop at checking the DNS records.
How DNS Affects Business Email
DNS is essential to business email because mail servers use domain records to determine where messages should be delivered and to check certain aspects of email authentication.
MX records direct incoming mail to the relevant receiving servers. TXT records may be used to publish SPF, DKIM and DMARC information, helping receiving systems evaluate whether messages are authorised and whether they align with the domain’s policies.
Incorrect email DNS configuration can lead to undelivered messages, failed authentication or increased spam classification.
Businesses should be especially careful when migrating hosting or changing name servers. Website and email services can use different providers, so moving the website does not automatically mean that email should move as well.
Before changing DNS, document the existing mail configuration and confirm the exact records required by the current email provider.
For organisations that need professional email accounts for their teams, Tremhost business email hosting is a service worth exploring.
How DNS Relates to Website Security
DNS is also an important part of website security. Incorrect or compromised DNS settings can redirect users to the wrong destination, interrupt legitimate services or affect the availability of a website.
Good DNS management starts with protecting the accounts that control the domain and its DNS configuration.
Use strong, unique passwords and multi-factor authentication where available. Restrict access to authorised administrators, keep recovery details current and review changes to important records.
When changing DNS, verify the destination addresses and avoid adding records that have not been requested or properly understood.
DNSSEC, or Domain Name System Security Extensions, can add cryptographic validation to DNS responses. When correctly configured across the relevant chain of trust, it helps resolvers detect certain forms of DNS data tampering. It does not encrypt DNS queries or protect a website against every type of attack.
Businesses can also use appropriate DNS providers and security services to help manage availability and protect their web applications. Tremhost’s Cloudflare solutions are worth reviewing when evaluating DNS-related services and broader website protection.
The correct features depend on the selected service and configuration. DNS security should form part of a wider strategy that includes secure hosting, software updates, access control and reliable backups.
What Happens When You Change Hosting Providers?
Moving a website to a new hosting provider often requires changes to DNS, but the exact steps depend on the existing setup.
If you keep your current DNS provider, you may only need to update the relevant website records. If you change name servers, you must ensure that the new DNS zone contains all records required by the domain’s services.
A careful migration should include the following considerations:
First, prepare the new hosting environment and confirm that the website works there before directing public traffic to it.
Next, record the current DNS configuration, paying particular attention to website records, MX records, email authentication and third-party verification entries.
Then, make the required DNS changes according to the migration plan. Where practical, plan the change around a suitable maintenance window and consider the relevant TTL values in advance.
Finally, test the website and email services after the change. Monitor for unexpected errors and retain access to the previous environment until you have confirmed that the migration is successful and any required rollback period has passed.
The main objective is to move the website without accidentally disrupting services that depend on the same domain.
Final Thoughts: DNS Keeps Your Online Services Connected
DNS is one of the fundamental systems behind the internet. It helps browsers locate websites, mail servers receive messages and applications discover the services they need.
Understanding A, AAAA, CNAME, MX, TXT and NS records makes it easier to manage a domain, troubleshoot website problems and plan hosting migrations.
For businesses, the key is to treat DNS as part of the overall infrastructure rather than an isolated setting. Keep records accurate, protect administrative access, document changes and verify your website and email after making adjustments.
If you are preparing to launch a website or move an existing one, explore Tremhost’s hosting services and business email hosting to review options for your online presence.
A well-configured DNS setup helps customers reach the right services, but reliable hosting, secure applications and careful maintenance are what keep those services working well.
Frequently Asked Questions
What does DNS stand for?
DNS stands for Domain Name System. It translates domain names into information that computers use to locate internet services.
How does DNS work in simple terms?
DNS acts like an internet address directory. When you enter a domain name, a resolver finds the relevant DNS information so your browser can connect to the appropriate server.
What is the difference between DNS and web hosting?
DNS helps direct requests to the correct services, while web hosting provides the environment used to serve and operate a website. A domain name identifies the online address people use.
What are the most common DNS record types?
Common records include A for IPv4 addresses, AAAA for IPv6 addresses, CNAME for hostname aliases, MX for incoming email routing, TXT for text-based information and verification, and NS for authoritative name servers.
How long does DNS propagation take?
There is no fixed time for every change. The result depends on caching, TTL values, resolver behaviour, delegation and the type of DNS change made.
Can DNS affect business email?
Yes. Incorrect MX records can prevent incoming email from reaching the correct servers. Incorrect SPF, DKIM or DMARC configuration can also affect email authentication.
Will changing DNS delete my website?
Changing DNS records does not itself delete website files. However, it can direct visitors away from the server containing the website, making it appear unavailable. Always confirm the intended changes before applying them.
What is the difference between changing DNS records and changing name servers?
Changing DNS records updates specific information within a DNS zone. Changing name servers changes which authoritative servers are responsible for the domain’s DNS zone. The latter requires particular care because the new zone must contain all necessary records.
What is DNSSEC?
DNSSEC is a set of extensions that enables cryptographic validation of DNS data. It helps protect against certain forms of DNS data manipulation but does not encrypt DNS queries or replace other security controls.
Do I need to manage DNS myself?
Not necessarily. Your registrar, hosting provider or DNS service may manage the configuration for you. However, understanding the basics helps you avoid service interruptions when changing hosting, email providers or other online services.
