In computing, DNS stands for Domain Name System. It acts as the “phonebook of the internet,” translating human-friendly domain names (like google.com) into numerical IP addresses (like 142.250.190.14) that computers use to communicate.
How DNS Works
When you type a URL into your browser, a DNS lookup occurs through a hierarchy of servers:
Recursive Resolver: Your first point of contact (usually provided by your ISP), which searches for the address on your behalf.
Root Nameserver: Directs the resolver to the correct Top-Level Domain (TLD) server based on the extension, such as .com or .org.
TLD Nameserver: Points to the Authoritative Nameserver for that specific domain.
Authoritative Nameserver: Holds the final, definitive IP address and returns it to the resolver.
Key Concepts
DNS Caching: To speed up browsing, devices and browsers temporarily store previously resolved IP addresses so they don’t have to repeat the full lookup every time.
DNS Records: These are instructions stored on servers. Common types include:
A Record: Maps a domain to an IPv4 address.
AAAA Record: Maps a domain to an IPv6 address.
MX Record: Directs emails to the correct mail server.
CNAME Record: Aliases one domain name to another.
Public DNS: While most people use their ISP’s default settings, you can switch to free public providers like Google Public DNS (8.8.8.8) or Cloudflare (1.1.1.1) for better speed, privacy, or security.
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