DNS Fundamentals

How DNS works, record types, resolution, propagation, caching, zones, and the infrastructure that powers domain name lookups.

DNS is the system that translates domain names into IP addresses. Understanding how it works — resolution, propagation, caching, zones — is essential for anyone managing a website or online service. These articles cover the core concepts behind DNS.

For a comprehensive overview, see our The Complete DNS Guide for Website Owners.

How DNS Resolution Works (Step by Step)

A step-by-step guide to how DNS resolution works, from browser cache to authoritative nameserver. Understand recursive and iterative queries.

DNS Propagation: What It Is and Why It Takes Time

Learn what DNS propagation really is, why it takes time, and how TTL affects how quickly DNS changes appear worldwide. Debunk the 48-hour myth.

DNS Caching and TTL: What They Mean for Your Site

Understand how DNS caching works at every level, what TTL values mean, how to choose the right TTL, and best practices for faster propagation.

DNS TTL Explained: How to Choose the Right Value

What DNS TTL is, how caching works at each level, common TTL values for different situations, and how to choose the right TTL for your records.

What Is a DNS Zone?

What DNS zones are, how they differ from domains, the structure of a zone file, zone delegation, and how zones enable the distributed nature of DNS.

DNS Replication: How It Works and How to Verify

How DNS replication works between primary and secondary nameservers, zone transfers, AXFR and IXFR protocols, and how to verify that replication is working correctly.

What Is DNS Failover? How It Keeps Sites Online

How DNS failover works, how health checks trigger automatic record updates, TTL considerations, provider options, and when to use DNS-based failover vs alternatives.

DNS over HTTPS (DoH) Explained

What DNS over HTTPS is, how it encrypts DNS queries over HTTPS, how DoH compares to DoT and traditional DNS, and how to enable it in your browser or system.

What Is a DNS Server? How DNS Servers Work

What DNS servers are, how they work, the four types involved in DNS resolution (recursive, root, TLD, authoritative), public DNS options, and how to find or change your DNS server.

What Are Nameservers? A Practical Guide

Nameservers are the backbone of DNS. This guide explains what nameservers do, how they work, why your registrar asks you to set them, and how to check and change them.

What Is a Subdomain? How Subdomains Work

What subdomains are, how they work in DNS, common uses, how to create them, and the SEO and technical implications of using subdomains vs subdirectories.

Why DNS Records Matter More Than You Think

DNS records are the invisible routing layer behind every website, email, and online service. Learn why getting them right is critical for uptime and security.

What Happens When DNS Records Change Unexpectedly

Understand the impact of unexpected DNS record changes, how unauthorized modifications happen, and how to detect and respond to DNS incidents.