If you've ever wondered how typing a website address into your browser magically takes you to the right place, the answer lies in domains and DNS. This guide will explain these fundamental concepts in plain English, helping you understand how the internet finds and connects you to websites.
Key Insight: Think of DNS as the internet's phone book—it translates human-friendly website names (like expeed.com.au) into computer-friendly numbers (IP addresses) that computers use to find each other.
What Is a Domain Name?
A domain name is the human-readable address you type into your browser to visit a website. Instead of remembering a string of numbers like 203.45.67.89, you can simply type expeed.com.au.
Parts of a Domain Name
- Top-Level Domain (TLD): The last part (.au, .com, .org, .net). Country-specific TLDs like .au indicate the country.
- Second-Level Domain: Often indicates the type (.com for commercial, .org for organisations).
- Domain Name: The unique name you register (expeed, google, facebook).
- Subdomain: Optional prefix like "www" or "mail" that points to different services.
What Is DNS?
DNS stands for Domain Name System. It's the technology that converts domain names into IP addresses—the numerical addresses that computers use to identify each other on the internet.
Every device connected to the internet has an IP address (like 203.45.67.89 for IPv4 or 2001:0db8:85a3:0000:0000:8a2e:0370:7334 for IPv6). DNS makes the internet usable by letting us use memorable names instead of these numbers.
How DNS Works (Simplified)
- 1You type a URL
You enter "expeed.com.au" in your browser.
- 2Browser asks DNS resolver
Your browser asks a DNS resolver (usually provided by your ISP) for the IP address.
- 3Resolver queries DNS servers
The resolver works through a hierarchy of DNS servers to find the answer.
- 4IP address returned
The resolver returns the IP address to your browser.
- 5Browser connects
Your browser uses the IP address to connect to the website's server.
What Are Nameservers?
Nameservers are specialized servers that store DNS records for domain names. When you register a domain, you point it to specific nameservers that will respond to DNS queries about your domain.
How Nameservers Work
- • Your domain registrar stores your nameserver settings
- • Nameservers hold the DNS records for your domain
- • When someone looks up your domain, the nameservers provide the answer
- • Most domains have 2+ nameservers for redundancy
Example Nameservers
ns1.hostingprovider.com
ns2.hostingprovider.com
Nameservers are typically provided by your hosting company or DNS provider.
Nameservers vs DNS Records
Nameservers tell the internet where to find your DNS records. DNS records(stored on those nameservers) tell the internet what to do—which server hosts your website, which handles your email, etc.
Multiple DNS Records, One Active Set
Here's something that often catches people off guard: you can have DNS records for your domain set up at multiple providers at the same time. For example, your current hosting provider might have a full set of DNS records for your domain, and your new hosting provider might also have a complete set ready to go. Both sets exist simultaneously—but only one set is actually active.
The set that the internet pays attention to is determined entirely by your domain registration's nameserver configuration. Your domain registrar (the company where you registered your domain) stores a record of which nameservers are authoritative for your domain. When anyone on the internet looks up your domain, they are directed to those nameservers—and only those nameservers—to get your DNS records.
The DNS records sitting on any other provider's nameservers are completely ignored by the internet until you update your domain registration to point to them.
Example: Switching Hosting Providers
Imagine you're moving your website from Host A to Host B. Here's what the setup might look like:
Host A (Current)
ns1.hosta.com ← Active
ns2.hosta.com ← Active
DNS records here are what the internet sees
Host B (New)
ns1.hostb.com ← Inactive
ns2.hostb.com ← Inactive
DNS records here are ignored until you switch
Both hosts have DNS records configured for your domain, but because your domain registration still points to Host A's nameservers, the internet only uses Host A's DNS records. When you're ready to switch, you update your nameservers at your domain registrar to point to Host B. After propagation, the internet starts using Host B's DNS records instead.
Why this matters: This is actually a useful feature when migrating between providers. You can set up all your DNS records at the new provider before switching nameservers, ensuring everything is ready. Then when you update the nameservers, the transition is seamless. It also means that creating DNS records at a new provider won't affect your live website until you deliberately change your nameserver configuration.
Common DNS Record Types
DNS records are instructions stored on nameservers. Different record types serve different purposes:
A Record (Address)
Points a domain or subdomain to an IPv4 address. This is the most fundamental record type—it tells browsers where to find your website.
expeed.com.au → 203.45.67.89AAAA Record
Same as an A record, but for IPv6 addresses. As the internet transitions to IPv6, these are becoming more important.
CNAME Record (Canonical Name)
Points one domain to another domain (not an IP address). Useful for subdomains or pointing to services like cloud platforms.
www.expeed.com.au → expeed.com.auMX Record (Mail Exchange)
Specifies which servers handle email for your domain. Without correct MX records, you won't receive emails at your domain.
expeed.com.au → mail.expeed.com.au (priority 10)TXT Record
Stores text information. Commonly used for email authentication (SPF, DKIM, DMARC), domain verification, and security policies.
NS Record (Nameserver)
Specifies which nameservers are authoritative for a domain. These are typically set at your domain registrar.
Understanding TTL (Time to Live)
Every DNS record has a TTL value (measured in seconds) that tells other servers how long to cache (remember) the record before checking for updates.
Common TTL Values
- 300 (5 min): When you expect changes soon
- 3600 (1 hour): Common default for active sites
- 86400 (24 hours): For stable, rarely-changed records
Why TTL Matters
- • Lower TTL = faster propagation of changes
- • Higher TTL = better performance (less lookups)
- • Lower TTL before making changes, raise after
Pro Tip: If you're planning to change hosting providers or make DNS changes, lower your TTL values to 300 seconds a day or two before the change. This ensures the new settings propagate faster when you make the switch.
DNS Propagation
When you change DNS records, the changes don't take effect instantly worldwide. DNS propagation is the time it takes for DNS changes to spread across all servers on the internet.
- Propagation typically takes 15 minutes to 48 hours
- Different users may see different results during propagation
- Lower TTL values before changes speed up propagation
- Some ISPs cache more aggressively than others
Summary: Key Concepts
- 1Domain names are human-friendly addresses for websites
- 2DNS translates domain names to IP addresses
- 3Nameservers store and serve DNS records for your domain
- 4DNS records (A, MX, CNAME, etc.) define where to send traffic
- 5TTL controls how long DNS records are cached
- 6Propagation is the time for DNS changes to spread globally
Next Steps
Now that you understand domains and DNS, you're ready to learn about switching hosting providers—a process that relies heavily on proper DNS management.
Understanding domains and DNS is fundamental to managing your online presence. While these concepts can seem technical at first, they're really quite straightforward once you understand the basics. If you need help managing your domain or DNS settings, our team at Expeed Technology is here to assist.