Glossary term
What is DNS (Domain Name System)?
DNS stands for Domain Name System.
In DevOps
The internet's phone book. Turns a name like yourapp.com into an IP address like 52.66.12.9.
Learn it properly · DevOpsLesson 3: DNS Deep Dive: From Domain Name to ServerHow a domain name turns into a server address — records, TTL, Route 53, and the one wildcard record that serves unlimited customer subdomains for a multi-tenant SaaS.In System Design
Turns human names into IP addresses. Example: The internet's phone book: amazon.com → 52.94.236.248.
Learn it properly · System DesignLesson 1: What Happens When You Type a URL and Press Enter?The one second between pressing Enter and seeing a page hides a DNS lookup, a trip through a dozen routers, two handshakes and a server doing real work. Every later lesson zooms into one part of that journey.In The Browser Contract
The internet's phone book. It turns a name like react.dev into an IP address (the number of a server). Answers are saved for a set time (the TTL).
Learn it properly · The Browser ContractLesson 0: What Happens When You Type a URL (The Full Version)The full trip from pressing Enter to seeing pixels: DNS, TCP, TLS, HTTP, then reading the page and painting it. Caches skip most steps. Every other lesson in this series fits on this map.