What is DNS?

DNS, or the Domain Name System, is the internet's phonebook—it translates human-friendly domain names like google.com into the numerical IP addresses that computers use to find each other. Every time you visit a website, send an email, or stream a video, DNS works behind the scenes in milliseconds to make the connection possible.

This guide covers how DNS works, the types of servers involved in every lookup, and practical steps for troubleshooting common DNS issues.

What is DNS

DNS, or the Domain Name System, is the internet's phonebook. It translates human-friendly website names like google.com into numerical IP addresses like 142.250.186.46 that computers use to locate and connect to each other. This translation process, called DNS resolution, happens instantly behind the scenes every time you visit a website.

Without DNS, you would have to memorize long strings of numbers for every website you wanted to visit. Instead, DNS lets you type simple, memorable domain names into your browser while the system handles the complex work of finding the correct server.

• Domain name: The human-readable website address you type, such as facebook.com
• IP address: The numerical identifier that computers use to locate each other on the internet
• DNS resolution: The process of converting a domain name into its corresponding IP address

What Does DNS Stand For

DNS stands for Domain Name System. You might occasionally see it called Domain Name Service, though Domain Name System is the more accurate and widely accepted term.

The name reflects exactly what it does. It's a system for managing domain names across the entire internet, functioning as a massive, distributed directory that keeps track of which domain names correspond to which IP addresses.

What Does DNS Do

DNS converts the domain names you type into your browser into the IP addresses that computers actually use to communicate. Every device connected to the internet has a unique IP address, and DNS acts as the translator between what humans find easy to remember and what machines require to function.

This translation happens so quickly that most people never realize it's occurring. When you click a link or type a URL, DNS works in milliseconds to ensure your browser knows exactly where to go.

How Does DNS Work

DNS operates through a network of servers that work together in a hierarchy to answer your requests. When you type a website address, your computer doesn't magically know where that site lives. It has to ask a series of DNS servers to find out.

The DNS Query Process

A DNS query is simply a request for information. When you enter a URL into your browser, your device sends out a query asking, "What is the IP address for this domain name?" This query then travels through multiple servers until it finds the answer.

The process involves several specialized servers, each with a specific role. Rather than one server knowing everything, the workload is distributed across millions of servers worldwide.

How DNS Resolution Translates Names to Addresses

DNS resolution works like a chain of referrals. Your initial request goes to a resolver, which then contacts other servers on your behalf. Each server in the chain either provides the answer or points to another server that might know.

This distributed approach makes DNS incredibly resilient. If one server fails, others can still handle requests, keeping the internet functional even when individual components experience problems.

Types of DNS Servers

Four main types of DNS servers work together to resolve your queries. Each plays a distinct role in the lookup process.

Recursive DNS Resolver

The recursive resolver is your first point of contact in the DNS lookup process. Usually provided by your internet service provider, this server acts as a middleman between you and the rest of the DNS infrastructure. It does the heavy lifting of tracking down the IP address you're looking for.

Root Name Server

Root name servers sit at the top of the DNS hierarchy. They don't know specific IP addresses, but they know which servers to ask next. When a resolver receives a query, it first contacts a root server to get pointed in the right direction.

TLD Name Server

TLD stands for Top-Level Domain, referring to extensions like .com, .org, or .net. TLD servers manage all domain names that share a common extension. When the root server identifies that you're looking for a .com address, it directs your query to the appropriate TLD server.

Authoritative DNS Server

The authoritative server holds the actual DNS records for a specific domain. This is where the final answer lives. When your query reaches the authoritative server, it returns the IP address that corresponds to the domain name you requested.

Steps in a DNS Lookup

Here's what happens when you type a website address into your browser:

1. User enters a domain name in the browser

You type www.example.com into your browser's address bar and press enter.

2. Browser checks local cache

Your browser first checks whether it already has the IP address saved from a previous visit. If it does, the lookup ends here.

3. Query goes to recursive resolver

If the browser doesn't have the answer cached, it sends a query to the recursive resolver, typically operated by your ISP.

4. Resolver queries root name server

The resolver contacts a root name server to find out which TLD server handles the domain extension.

5. Root server directs to TLD server

The root server responds with the address of the appropriate TLD server based on the domain extension.

6. TLD server points to authoritative server

The TLD server identifies which authoritative server holds the records for the specific domain.

7. Authoritative server returns the IP address

The authoritative server sends the IP address back through the chain to the resolver.

8. Website loads in the browser

Your browser uses the IP address to connect to the web server and display the requested page.

What is DNS Caching

DNS caching stores the results of previous lookups to speed up future requests. Instead of going through the entire lookup process every time, cached results provide instant answers.

Browser DNS Cache

Your web browser maintains its own cache of recent DNS lookups. This is the fastest cache to check since it's stored locally on your device.

Operating System DNS Cache

Your computer's operating system keeps a separate DNS cache that all applications can access. Even if your browser doesn't have a cached result, your operating system might.

Resolver DNS Cache

DNS resolvers also cache results, which benefits all users who share that resolver. When one person looks up a popular website, the cached result can serve thousands of subsequent requests.

Why DNS Matters for the Internet

Makes the Internet Human-Friendly

DNS transforms the internet from a network of numbers into something people can actually use. Remembering "google.com" is far easier than memorizing "142.250.186.46."

Impacts Website Speed and Performance

Fast DNS resolution contributes to quicker page load times. A slow DNS lookup can add noticeable delays before a website even begins loading.

Provides a Layer of Security

DNS can be configured to block access to known malicious websites. Many organizations use DNS filtering as a first line of defense against cyber threats.

How to Find Your DNS Address

Finding your DNS settings varies by device and operating system:

• Windows: Open Command Prompt and type ipconfig /all
• Mac: Go to System Preferences, then Network, then Advanced, then DNS
• Router: Access your router's admin panel, typically at 192.168.1.1

How to Fix Common DNS Problems

DNS Server Not Responding Error

This error typically indicates a connectivity issue or server outage. Restarting your router or switching to a public DNS provider like Google (8.8.8.8) or Cloudflare (1.1.1.1) often resolves the problem.

DNS Cache Corruption

Outdated or corrupted cache entries can cause websites to fail to load. Flushing your DNS cache clears old entries and forces fresh lookups. On Windows, you can do this by typing ipconfig /flushdns in Command Prompt.

Incorrect DNS Configuration

Misconfigured DNS settings can prevent proper resolution. Resetting your DNS to automatic or manually entering a reliable public DNS server typically fixes configuration issues.

DNS Security Best Practices

Protect Against DNS Spoofing

DNS spoofing occurs when attackers redirect your traffic to malicious websites by providing false DNS responses. Using trusted DNS providers with built-in security features helps mitigate this risk.

Implement DNSSEC

DNSSEC, or DNS Security Extensions, adds authentication to DNS responses. This protocol helps verify that the DNS information you receive actually comes from a legitimate source rather than an attacker.

Use Encrypted DNS Protocols

DNS over HTTPS (DoH) and DNS over TLS (DoT) encrypt your DNS queries, preventing others from seeing which websites you're visiting. Many modern browsers now support both protocols.

Strengthening Your Organization's Digital Infrastructure

Understanding foundational internet technologies like DNS helps organizations make informed decisions about their digital systems. Just as DNS connects users to the right online destinations, effective internal systems connect employees to the right opportunities and resources.

Organizations focused on building strong infrastructure benefit from platforms that streamline connections and improve efficiency. Book a demo to see how Engagedly helps organizations strengthen their talent management systems.

Frequently Asked Questions About DNS

Is 1.1.1.1 still the best DNS?

Cloudflare's 1.1.1.1 remains a popular choice for its speed and privacy features. However, Google Public DNS (8.8.8.8) and other providers also perform well, and the best option often depends on your geographic location and specific priorities.

What is the difference between DNS and an IP address?

DNS is the system that performs translations, while an IP address is the numerical identifier being looked up. Think of DNS as the phonebook and the IP address as the phone number.

Can changing your DNS server improve internet speed?

Switching to a faster public DNS provider may reduce lookup times, particularly if your ISP's DNS servers are slow. However, actual browsing speed depends on many factors beyond DNS resolution.

How long does DNS propagation take?

DNS propagation refers to the time for DNS changes to spread globally. This can take anywhere from a few minutes to 48 hours. The duration depends on TTL (Time to Live) settings and how aggressively servers cache records.

What happens when DNS servers go down?

When DNS servers fail, browsers cannot translate domain names to IP addresses. Websites appear unreachable even though the actual web servers may be functioning normally.

Should you use your ISP's DNS or a public DNS provider?

Public DNS providers like Google or Cloudflare often offer faster speeds and better privacy protections than default ISP DNS. Either option works reliably for most users, though public providers typically offer additional security features.