Quick Answer

DNS (Domain Name System) is the system that translates human-readable domain names such as example.com into IP addresses that computers use to locate servers on the Internet.

For example, instead of remembering an IP address for every website, you enter a domain name in your browser. DNS finds the appropriate IP address and helps your computer connect to the server hosting that website.

DNS is often described as the address book or phonebook of the Internet.

DNS is not limited to websites. DNS records are also important for services such as:

• Websites and web applications
• Email delivery
• Subdomains
• Cloud services
• Domain verification
• Email authentication
• Load distribution and service discovery
• Reverse DNS lookups

What Is DNS?

DNS stands for Domain Name System.

Computers communicate over IP networks using IP addresses. Humans, however, generally find names much easier to remember than numeric addresses.

For example:

example.com

is easier to remember than an IPv4 address such as:

192.0.2.10

DNS provides the mechanism for associating names with information such as IP addresses.

ICANN describes DNS as the system that connects domain names with IP addresses and makes navigating the Internet easier.

A simplified representation is:

Domain Name
     ↓
DNS Lookup
     ↓
IP Address
     ↓
Destination Server

Your browser can then communicate with the destination server using the address returned through DNS resolution.

Why Do We Need DNS?

Imagine having to remember an IP address for every website you visit.

Instead of entering:

example.com

you might have to remember something similar to:

192.0.2.10

And if the server's IP address changed, users would have to learn the new address.

DNS separates the human-friendly name from the underlying network address.

The DNS record can therefore be changed when a website moves to another server without requiring users to start using a different domain name.

This makes the Internet considerably easier to manage and use.

How Does DNS Work?

Suppose you enter:

www.example.com

into your browser.

A simplified DNS resolution process looks like this:

You enter www.example.com
          ↓
Browser / Operating System
          ↓
DNS Recursive Resolver
          ↓
Root DNS Server
          ↓
TLD DNS Server
          ↓
Authoritative DNS Server
          ↓
DNS Record / IP Address
          ↓
Your Computer
          ↓
Website Server

In practice, caching often means that some of these steps do not need to occur for every lookup.

A typical uncached DNS lookup can involve a recursive resolver, root nameserver, top-level-domain nameserver and authoritative nameserver.

Step 1: You Enter a Domain Name

You type a domain such as:

example.com

into your browser.

The computer needs information about where that domain should be reached.

Step 2: Local DNS Cache Is Checked

Before performing a complete DNS lookup, previously resolved information may already be cached.

DNS-related caching can occur at several levels, including the browser, operating system and recursive resolver.

If a valid cached answer is available, DNS resolution can be completed much faster.

Step 3: DNS Resolver Receives the Request

If the required answer is not available locally, the query is normally sent to a recursive DNS resolver.

The resolver may be operated by:

• Your Internet Service Provider
• Your organization
• A public DNS provider
• Another configured DNS service

The resolver attempts to obtain the requested DNS information and return it to the client.

Step 4: Root DNS Infrastructure Is Consulted

For an uncached lookup, the resolver can start with a root nameserver.

The root server does not normally provide the final IP address for the website. Instead, it directs the resolver toward the appropriate top-level-domain infrastructure.

Step 5: TLD Nameserver Is Queried

TLD means Top-Level Domain.

Examples include:

.com
.org
.net
.in

The TLD nameserver helps identify the authoritative nameservers responsible for the requested domain.

Step 6: Authoritative Nameserver Is Queried

The authoritative nameserver contains the authoritative DNS information for the domain.

Cloudflare describes an authoritative DNS server as the server responsible for DNS resource records and capable of providing the final answer for records for which it is authoritative.

For example, it might return an A record such as:

example.com → 192.0.2.10

Step 7: The Result Is Returned

The DNS resolver returns the result to your computer.

The answer may also be cached for future queries according to caching rules and the record's TTL.

Step 8: Your Browser Connects to the Server

Once the necessary IP address is known, the browser can establish the appropriate network connection to the destination server.

DNS has therefore helped answer:

Where should this domain name be reached?

The web protocols involved after that—such as HTTPS—handle the actual communication with the web server.

What Is a DNS Server?

A DNS server is a server involved in storing, resolving or supplying DNS information.

It is useful to understand that "DNS server" can refer to systems performing different roles.

Four important categories involved in a typical uncached lookup are:

1. Recursive resolver
2. Root nameserver
3. TLD nameserver
4. Authoritative nameserver

 

Recursive DNS Resolver

The recursive resolver receives a DNS query from the client.

It may return an answer from its cache or perform additional DNS queries to obtain the required information.

Root Nameserver

Root nameservers operate at the top of the public DNS hierarchy.

They help direct a resolver toward the appropriate TLD nameservers.

TLD Nameserver

A TLD nameserver handles information associated with a top-level domain such as:

.com
.net
.org
.in

It helps direct the resolver toward the authoritative nameservers for a particular domain.

Authoritative Nameserver

An authoritative nameserver contains the authoritative DNS records for a domain or DNS zone for which it is responsible.

For example, the authoritative DNS configuration may contain:

example.com      A       192.0.2.10
www              CNAME   example.com
mail             A       192.0.2.20

What Are DNS Records?

DNS records are entries containing information and instructions associated with a domain.

Different record types perform different jobs.

Cloudflare's current DNS documentation describes DNS records as information about a domain used to make websites, applications and other web services available.

Some of the most important DNS record types are:

Record	Main Purpose
A	Maps a hostname to an IPv4 address
AAAA	Maps a hostname to an IPv6 address
CNAME	Aliases one hostname to another hostname
MX	Specifies mail servers for a domain
TXT	Stores text data used for verification, policies and other purposes
NS	Identifies authoritative nameservers
SOA	Contains administrative information about a DNS zone
PTR	Used for reverse DNS mapping
SRV	Identifies hosts and ports for particular services
CAA	Specifies which certificate authorities may issue certificates for a domain

A Record

An A record maps a hostname to an IPv4 address.

Example:

example.com → 192.0.2.10

Conceptually, a DNS zone might contain:

Type: A
Name: @
Value: 192.0.2.10

Here, @ commonly represents the zone apex in DNS management interfaces.

A records are among the fundamental DNS records used to direct traffic to IPv4 addresses.

AAAA Record

An AAAA record performs a similar function for IPv6.

Example:

example.com → 2001:db8::10

Cloudflare's current documentation confirms that A and AAAA records map names to IPv4 and IPv6 addresses respectively.

CNAME Record

CNAME stands for Canonical Name.

It allows one hostname to act as an alias of another hostname.

For example:

www.example.com → example.com

or:

portal.example.com → service.example.net

A CNAME points to another hostname rather than directly specifying an IP address.

MX Record

MX stands for Mail Exchange.

MX records identify the mail servers responsible for accepting email for a domain.

For example:

example.com
       ↓
MX Record
       ↓
Mail Server

A domain can have multiple MX records with different priorities.

Incorrect MX configuration can cause incoming email delivery problems even when the website itself is working normally.

TXT Record

A TXT record stores text information in DNS.

TXT records are widely used for tasks such as:

• Domain ownership verification
• SPF email authorization
• DKIM-related configuration
• DMARC policies
• Service verification
• Security policies

For example, an SPF TXT record might begin with:

v=spf1

The complete value depends on the organization's actual email infrastructure.

Important: Do not copy SPF, DKIM or DMARC records from another domain. These records must match your own email configuration.

NS Record

NS stands for Nameserver.

NS records indicate the authoritative nameservers for a DNS zone/domain delegation.

Cloudflare describes an NS record as identifying which DNS server is authoritative for the domain.

Example:

ns1.example-dns.net
ns2.example-dns.net

Changing authoritative nameservers is a significant DNS change because it can change where the Internet obtains authoritative DNS information for your domain.

SOA Record

SOA stands for Start of Authority.

The SOA record contains administrative and operational information about a DNS zone, including values used by DNS servers for zone management.

It commonly contains information relating to:

• Primary nameserver
• Administrative contact representation
• Zone serial number
• Refresh interval
• Retry interval
• Expiry
• Negative caching parameters

Most ordinary website owners do not need to manually modify the SOA record.

PTR Record and Reverse DNS

Normal DNS commonly resolves:

Domain Name → IP Address

Reverse DNS performs the opposite type of lookup:

IP Address → Hostname

PTR records are used for reverse DNS.

Reverse DNS is particularly important in server administration and email infrastructure. For public IP addresses, PTR records are normally controlled through the organization that controls the IP address, such as your hosting provider or ISP, rather than through the ordinary forward DNS zone alone.

What Is TTL in DNS?

TTL stands for Time to Live.

A DNS record's TTL influences how long caching resolvers may retain the record before obtaining a fresh answer.

For example:

TTL = 3600

represents:

3600 seconds = 1 hour

Cloudflare's DNS documentation notes that DNS records have TTL values that determine how caching and refresh behavior works.

TTL is important when changing:

• Website hosting
• Server IP addresses
• Email providers
• MX records
• DNS infrastructure

A shorter TTL before a planned migration can sometimes help caches refresh sooner, although DNS change visibility depends on more than simply calling the process "propagation."

What Is DNS Propagation?

The phrase DNS propagation is commonly used to describe the period during which users and DNS resolvers begin seeing changed DNS information.

Suppose you change:

example.com

Old IP:
192.0.2.10

New IP:
192.0.2.20

Some recursive resolvers may still have the previous record cached until its cached TTL expires.

As caches refresh, they obtain the updated DNS information.

Therefore, DNS changes may not appear everywhere at exactly the same moment.

Important

There is no universal rule that every DNS record change always requires exactly 24, 48 or 72 hours.

The actual experience depends on factors such as:

• Previous TTL
• Resolver caching
• The type of DNS change
• Nameserver/delegation changes
• Local operating-system or browser caching
• ISP or enterprise DNS infrastructure

Public DNS Resolvers

Your ISP often provides DNS resolution automatically, but users and organizations can configure other recursive resolvers.

Examples include:

Provider	IPv4 DNS Addresses
Cloudflare	1.1.1.1, 1.0.0.1
Google Public DNS	8.8.8.8, 8.8.4.4

Cloudflare's current documentation lists its 1.1.1.1 service and Google 8.8.8.8 among examples of public recursive DNS services.

Changing DNS resolvers can sometimes help diagnose resolver-related problems, but it will not repair incorrect authoritative DNS records for your domain.

DNS Cache Explained

DNS caching improves performance by temporarily storing previously obtained DNS answers.

Without caching, repeated DNS queries would create unnecessary work and latency.

DNS information may be cached at several locations, including:

Browser
   ↓
Operating System
   ↓
Local Network / Router
   ↓
Recursive DNS Resolver

Not every network or browser implements caching in exactly the same way.

How to Check DNS in Windows

Windows includes several useful DNS diagnostic commands.

Using nslookup

Open Command Prompt and enter:

nslookup example.com

This can show the DNS server used for the query and the returned DNS information.

To query an MX record:

nslookup -type=mx example.com

To query NS records:

nslookup -type=ns example.com

To query TXT records:

nslookup -type=txt example.com

Check DNS Using PowerShell

Modern Windows versions also include the Resolve-DnsName PowerShell cmdlet.

Example:

Resolve-DnsName example.com

Check MX records:

Resolve-DnsName example.com -Type MX

Check TXT records:

Resolve-DnsName example.com -Type TXT

Check NS records:

Resolve-DnsName example.com -Type NS

For Windows administration and troubleshooting, Resolve-DnsName can provide more structured DNS information than basic nslookup output.

How to Check Your Current DNS Configuration in Windows

Open Command Prompt and run:

ipconfig /all

Look for:

DNS Servers

The listed addresses indicate which DNS servers Windows is currently configured to query for that network adapter.

How to Clear DNS Cache in Windows

Windows maintains a DNS resolver cache.

If a domain has recently changed IP addresses and your computer appears to be using stale information, clearing the local cache can sometimes help.

Open Command Prompt as Administrator and run:

ipconfig /flushdns

You should receive a confirmation that the DNS Resolver Cache was flushed.

Important

Flushing the Windows DNS cache only removes cached DNS information from that Windows computer.

It does not:

• Change authoritative DNS records
• Change your domain's nameservers
• Clear caches at your ISP
• Clear caches on public recursive DNS services
• Fix an incorrect A, MX, CNAME or other DNS record

Therefore, repeatedly running ipconfig /flushdns will not repair an incorrectly configured domain.

Common DNS Problems

DNS problems can affect websites, email and other Internet services.

Common symptoms include:

• Website not opening
• Domain resolves to the wrong server
• Email not arriving
• Subdomain not working
• Website works on one Internet connection but not another
• Recent DNS change appears for some users but not others
• "DNS server not responding"
• DNS_PROBE_FINISHED_NXDOMAIN
• Domain verification fails
• Email authentication checks fail

Website Works by IP but Not by Domain Name

Suppose:

http://192.0.2.10

reaches a server, but:

example.com

does not resolve correctly.

This can indicate a DNS-related issue, although successful access by IP does not prove that the website itself is configured correctly for hostname-based web hosting or HTTPS.

Check:

nslookup example.com

and compare the returned address with the expected server IP.

Website Works on One Computer but Not Another

Possible causes include:

• Different DNS resolvers
• Stale local DNS cache
• Browser cache
• VPN configuration
• Proxy configuration
• Hosts-file entry
• Security software
• Router DNS cache/configuration
• Enterprise DNS policies

Useful tests include:

nslookup example.com

and:

ipconfig /flushdns

You can also compare results against a known public resolver:

nslookup example.com 1.1.1.1

and:

nslookup example.com 8.8.8.8

Different answers can help identify whether the problem is resolver-related, although the results still need to be interpreted in the context of the domain's authoritative DNS configuration.

Email Not Working After DNS Changes

If a website works but email does not, check the domain's email-related DNS records.

Important records may include:

MX
TXT / SPF
DKIM
DMARC

The exact requirements depend on the email provider.

Incorrect MX records can prevent incoming email from reaching the intended mail system.

Incorrect SPF, DKIM or DMARC configuration can also affect authentication and deliverability.

Do not delete or replace email DNS records merely because they look unfamiliar. Verify the required values with your email provider first.

DNS vs IP Address

DNS / Domain Name	IP Address
Human-friendly naming system	Network addressing mechanism
Example: example.com	Example: 192.0.2.10
Easier for people to remember	Used by network protocols to identify destinations
DNS records can map names to addresses	Address identifies a network endpoint/interface

DNS does not replace IP networking. It provides a naming and lookup system that works with it.

DNS vs URL

These terms are also different.

Consider:

https://www.example.com/support/article?id=10

Here:

https

is the scheme.

www.example.com

is the hostname.

/support/article

is the path.

?id=10

is the query string.

DNS is primarily involved in resolving the hostname to information needed to locate the destination.

It does not translate the entire URL into an IP address.

DNS vs DHCP

DNS and DHCP perform different network functions.

DNS	DHCP
Domain Name System	Dynamic Host Configuration Protocol
Resolves names and DNS data	Supplies network configuration to clients
Can map hostnames to IP addresses	Can automatically assign IP addresses
Used on Internet and local networks	Commonly used inside networks

A DHCP server may provide clients with the addresses of DNS resolvers they should use, which is why the two technologies often work together.

DNS vs Nameserver

DNS refers to the overall Domain Name System.

A nameserver is a server participating in DNS, particularly one that answers queries for DNS information.

For a registered domain, the configured authoritative nameservers determine where resolvers should obtain authoritative DNS records for that domain.

For example:

Domain
example.com
      ↓
Authoritative Nameservers
ns1.example-dns.net
ns2.example-dns.net
      ↓
DNS Records
A
AAAA
MX
TXT
CNAME
etc.

What Happens If DNS Stops Working?

If the DNS resolver you depend on becomes unavailable, domain-name lookups may fail even though the underlying Internet connection is still active.

You might therefore see a situation where network connectivity exists but websites cannot be reached normally by hostname.

DNS outages can affect:

• Websites
• Email
• APIs
• Cloud applications
• Software licensing systems
• Remote services
• Business applications

This is why reliable DNS infrastructure is an important part of Internet and business-service availability.

Is DNS Secure?

Traditional DNS was designed primarily to provide distributed name resolution, not to provide end-to-end confidentiality for DNS queries.

Several technologies address different DNS security requirements.

DNSSEC

DNSSEC (Domain Name System Security Extensions) adds mechanisms that allow DNS data to be cryptographically validated.

Its purpose is to help protect against forged or manipulated DNS responses for signed zones.

DNSSEC does not encrypt ordinary DNS queries.

DNS over HTTPS (DoH)

DNS over HTTPS sends DNS queries through HTTPS.

This can protect DNS queries between the client and the configured DoH resolver from ordinary plaintext observation on that portion of the network.

DNS over TLS (DoT)

DNS over TLS encrypts DNS communication between the client and a compatible DNS resolver using TLS.

DNSSEC, DoH and DoT therefore address different aspects of DNS security and should not be treated as interchangeable technologies.

Can DNS Make the Internet Faster?

Sometimes.

DNS resolution is only one component of loading a website or Internet service.

A responsive DNS resolver may reduce lookup latency, particularly when answers are not already cached.

However, changing DNS servers will not automatically improve:

• Internet bandwidth
• Wi-Fi signal quality
• Server performance
• Website application performance
• File download capacity
• CPU performance

DNS can influence how quickly a destination is resolved, but it is not a general Internet speed booster.

Best Practices When Managing DNS

When changing production DNS records:

1. Back up or document the existing DNS zone.
2. Confirm the required values with your hosting or email provider.
3. Check TTL before major migrations.
4. Avoid deleting unfamiliar MX or TXT records without understanding them.
5. Verify A and AAAA records independently.
6. Verify email-related MX, SPF, DKIM and DMARC records.
7. Be especially careful when changing authoritative nameservers.
8. Test DNS from more than one resolver after important changes.
9. Keep domain registrar and DNS-provider accounts protected with strong authentication.
10. Consider DNSSEC when supported and correctly implemented by your DNS provider and registrar.

Warning

Incorrect DNS changes can make websites, email or other services unavailable.

Always record the existing DNS configuration before making significant changes.

Frequently Asked Questions

What does DNS stand for?

DNS stands for Domain Name System.

What does DNS do?

DNS provides a distributed naming system that allows applications to obtain information associated with domain names, including the IP addresses needed to reach Internet services.

Is DNS the same as an IP address?

No.

An IP address identifies a network destination, while DNS provides a naming and lookup system that can associate domain names with IP addresses and other information.

What is a DNS server?

A DNS server participates in the Domain Name System. Depending on its role, it may resolve queries, provide referrals or serve authoritative DNS records.

What is a DNS resolver?

A DNS resolver receives DNS requests from clients and obtains the required DNS information, often using cached data or queries to other DNS servers.

What is an authoritative DNS server?

An authoritative DNS server provides authoritative answers for DNS zones and records for which it is responsible.

What is an A record?

An A record maps a hostname to an IPv4 address.

What is an AAAA record?

An AAAA record maps a hostname to an IPv6 address.

What is an MX record?

An MX record identifies the mail servers responsible for accepting email for a domain.

What is a CNAME record?

A CNAME record makes one hostname an alias of another hostname.

What is a TXT record?

A TXT record stores textual DNS data and is commonly used for domain verification and email-security configuration such as SPF and related policies.

What is TTL?

TTL means Time to Live. It controls how long DNS information may remain cached before it needs to be refreshed.

How long do DNS changes take?

There is no single fixed time for every DNS change. Visibility depends on caching, previous TTL values, the type of record changed and whether authoritative nameserver/delegation information was modified.

Does ipconfig /flushdns speed up the Internet?

Normally, no.

It clears the Windows DNS resolver cache. It can help when stale cached DNS information is causing a name-resolution problem, but it does not increase Internet bandwidth.

Can DNS problems stop email?

Yes.

Incorrect MX or other email-related DNS configuration can interfere with email routing, authentication and delivery.

Can I change my DNS server?

Yes. Operating systems, routers and networks can often be configured to use alternative recursive DNS resolvers.

However, changing your resolver does not fix incorrect authoritative DNS records belonging to a domain.

Is 8.8.8.8 a DNS server?

Yes. 8.8.8.8 is an IPv4 address for Google Public DNS.

Is 1.1.1.1 a DNS server?

Yes. 1.1.1.1 is an IPv4 address for Cloudflare's public DNS resolver.

Final Recommendation / Conclusion

DNS is one of the fundamental technologies behind the Internet.

Its most familiar job is translating easy-to-remember domain names into information that computers can use to locate Internet services.

A simplified way to remember DNS is:

You enter a domain name
        ↓
DNS determines where it should go
        ↓
Your device obtains the required address
        ↓
It connects to the destination service

For website owners and IT administrators, understanding DNS is particularly important because incorrect DNS configuration can affect not only websites but also email, cloud applications, APIs, authentication and other business services.

At minimum, administrators should understand A, AAAA, CNAME, MX, TXT and NS records, know how TTL and caching affect DNS changes, and know how to perform basic diagnostics with tools such as nslookup and Resolve-DnsName.

 

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