What is an IP Address?
Every machine on a network has a unique identifier. Just as you would address a letter to send in the mail, computers use the unique identifier to send data to specific computers on a network. Most networks today, including all computers on the Internet, use the TCP/IP protocol as the standard for how to communicate on the network. In the TCP/IP protocol, the unique identifier for a computer is called its IP address. Read more...
Understanding the Relationship Between Domains and IP Addresses
Why Do We Need Domain Names?
While computers communicate using numeric IP addresses (like 142.250.80.46), humans find it much easier to remember meaningful names like "www.google.com". Domain names were created to make the internet user-friendly and accessible to everyone. Imagine having to memorize hundreds of IP addresses just to browse your favorite websites - it would be nearly impossible!
What is DNS (Domain Name System)?
The Domain Name System (DNS) is often called the "phone book of the internet." It's a distributed database system that translates human-readable domain names into machine-readable IP addresses. When you type a website address into your browser, DNS servers work behind the scenes to find the corresponding IP address so your browser can load the website.
For example, when you enter www.google.com in your browser, DNS translates it to an IP address like 142.250.80.46, allowing your computer to connect to Google's servers.
How Does Domain to IP Resolution Work?
When you type a domain name into your browser, here's what happens behind the scenes:
- Browser Cache Check: Your browser first checks if it has recently looked up this domain and has the IP address cached.
- Operating System Cache: If not found, your operating system checks its own DNS cache.
- Router Query: If still not found, the request goes to your router, which may have its own cache.
- ISP DNS Server: Your Internet Service Provider's DNS server is queried next.
- Recursive Search: If the ISP doesn't have the answer, it performs a recursive search starting from the root DNS servers, then the TLD (top-level domain) servers, and finally the authoritative name servers for that specific domain.
- Response: The IP address is returned and cached at multiple levels for faster future lookups.
This entire process typically takes just milliseconds, making it appear instantaneous to users.
Types of DNS Records
DNS uses different types of records to map domain names to various resources:
- A Record (Address Record): Maps a domain name to an IPv4 address (e.g., example.com → 192.0.2.1)
- AAAA Record: Maps a domain name to an IPv6 address (e.g., example.com → 2001:0db8::1)
- CNAME Record (Canonical Name): Creates an alias from one domain name to another (e.g., www.example.com → example.com)
- MX Record (Mail Exchange): Specifies the mail servers responsible for handling email for the domain
- TXT Record: Stores text information, often used for domain verification and email security (SPF, DKIM)
- NS Record (Name Server): Indicates which DNS servers are authoritative for the domain
DNS Caching and TTL (Time To Live)
To improve performance and reduce the load on DNS servers, DNS responses are cached at multiple levels. Each DNS record has a TTL (Time To Live) value that specifies how long the record should be cached before being refreshed. This is why changes to DNS records (like pointing a domain to a new IP address) can take time to propagate across the internet - it depends on the TTL values and existing caches.
Try Our Hostname to IP Tool
Want to see DNS resolution in action? Use our Hostname to IP Address Lookup Tool to convert any domain name to its corresponding IP address and see detailed DNS information.