DNS (Domain Name System)
Definition
The internet's phone book that translates human-readable domain names like example.com into numerical IP addresses that computers use to communicate.
The Domain Name System is a hierarchical, distributed naming system that resolves domain names to IP addresses. When you type a URL into your browser, DNS translates that human-readable address into the numeric IP address needed to locate the correct server.
DNS resolution involves multiple steps: the browser checks its cache, then the operating system cache, then queries a recursive DNS resolver (usually provided by your ISP), which may query root name servers, TLD name servers, and authoritative name servers for the domain.
DNS record types include A (maps domain to IPv4 address), AAAA (IPv6), CNAME (alias to another domain), MX (mail server), TXT (text data, often for verification), and NS (name server). Understanding DNS is essential for web hosting, email configuration, domain management, and troubleshooting connectivity issues.
Related Calculators
Related Terms
URL (Uniform Resource Locator)
techA web address that specifies the location of a resource on the internet, including the protocol, domain name, path, and optional parameters.
HTTP (HyperText Transfer Protocol)
techThe foundational protocol for data communication on the web, defining how messages are formatted and transmitted between clients and servers.
SSL/TLS (Secure Sockets Layer / Transport Layer Security)
techCryptographic protocols that provide secure communication over computer networks, encrypting data between a web server and browser.
CDN (Content Delivery Network)
techA geographically distributed network of servers that delivers web content to users from the nearest location, reducing latency and improving load times.
Related Articles
JSON Formatting Best Practices: Write Clean, Valid JSON
Master JSON formatting with best practices for syntax, nesting, and validation. Learn common errors, debugging tips, and how to write clean JSON data.
Regex Cheat Sheet: Essential Patterns Every Developer Needs
A practical regex reference guide with common patterns for emails, URLs, phone numbers, and more. Includes syntax explanations and real-world examples.
How to Generate Secure Passwords: Best Practices for 2026
Learn how to create strong, secure passwords that protect your accounts. Covers password length, complexity, managers, and multi-factor authentication.
Guide to QR Codes: How They Work, Types & Best Uses
Learn how QR codes work, the different types available, and best practices for creating and using them in marketing, payments, and information sharing.