DNS, or Domain Name System, is an online distributed naming system that translates domain names into IP addresses and provides relevant information associated with internet domains. Every time you open a website, use an online application, or perform an online activity, DNS is working in the background and translating domain names into numerical IP addresses.
Computers communicate using IP addresses, while people use domain names. DNS creates a connection between these two and allows people to use easy-to-remember domain names, e.g., example.com instead of a numerical IP address, by helping your device discover the IP address associated with that domain name.
For example:
Domain name: example.com
DNS lookup: Finds the relevant DNS record for the domain
IP address: Destination address provided by DNS
DNS is a fundamental part of the internet infrastructure and is a distributed and hierarchical system involving many DNS servers around the world, instead of a single server.
Why Do We Need DNS?
DNS is an important part of the internet infrastructure, and without DNS, using the internet would be less convenient, as you would have to remember an IP address for every website, email service, online store, application, and cloud service you use. Along with this, it would also become difficult for service providers to change their infrastructure without asking users to learn new addresses.
A DNS separates an online website’s or service’s human-readable name or domain name from the underlying network address. Plus, every time a website or service changes its servers or IP address, you don’t need to memorize anything new and can use the same domain name to access it.
For instance, a website can move its servers or change its IP address while continuing to use the same domain name. The website owner just has to update the relevant DNS records, and users can continue accessing the website by entering the same domain.
This makes DNS an important part of the internet infrastructure, as it provides not only convenience but also scalability and flexibility.
How Does DNS Work?
Many users wonder how DNS works and provides an IP address for the relevant domain name. Well, when you enter a domain name into your browser, several steps occur before the website begins loading, and DNS is an important part of it. Let’s take a look at how DNS works and how it provides the relevant DNS record for domains.
- When you enter a domain name into the address bar of a web browser, your device needs to determine the IP address associated with that domain name.
- The browser or operating system may already have a recent DNS result in its cache. If the cached information is still valid, the device may use it directly without performing a new lookup, and you can access the website.
- However, when cached information is not available, your device sends a DNS query to a recursive DNS resolver. This DNS resolver can be the one operated by your ISP, a public DNS provider, an organization, or another network service.
- The DNS resolver may already have the information because another user might have recently requested the information for the same domain. If the cached information is available, the DNS resolver returns the result immediately.
- If the information is not cached, the resolver can query the DNS hierarchy and ping the authoritative DNS server. The authoritative server ultimately provides the relevant DNS record for the domain.
- Once the DNS resolver receives the relevant DNS record for the domain, it returns the information to your device, and your browser can use that to access the IP address and communicate with the destination server.
The entire process is normally fast enough that users barely even notice it.
What Are Public DNS Servers?
A public DNS server or resolver is a DNS resolution service that users can configure instead of relying on the one that is supplied by their internet service provider (ISP). Users choose alternative public DNS servers for various reasons, including:
- Reliability
- Performance
- Privacy policies
- Security filtering
- Content filtering
However, it should be noted that changing DNS does not automatically make an internet connection faster. A DNS resolver can potentially respond more quickly to DNS queries, but it cannot increase your connection’s bandwidth. If you have a 100 Mbps internet connection, changing DNS does not turn it into a 500 Mbps connection.
Examples of Public DNS Servers:
Cloudflare
Primary IPv4: 1.1.1.1
Secondary IPv4: 1.0.0.1
Best for: High speeds and strict privacy (does not log IP addresses).
Google Public DNS
Primary IPv4: 8.8.8.8
Secondary IPv4: 8.8.4.4
Best for: Massive global network reliability and fast lookup performance