Meaning
Domain Name System; the hierarchical internet directory that translates human-friendly domain names into machine-readable IP addresses.
Three examples from work
Domain setup
DevOpsI updated our DNS A-records to point to the new Cloudflare edge proxy.
DevHow long will DNS propagation take globally?
Outage debugging
SupportClients in Australia cannot access our application.
DevOpsIt is always DNS; our regional nameserver was returning an expired record.
Migration planning
LeadLower the DNS TTL to 300 seconds before executing the server switchover.
DevOpsThat guarantees rapid cutover with zero downtime for end users.
Pronounce each letter: 'D-N-S'. Common phrases: 'DNS record', 'DNS propagation', 'DNS lookup', 'TTL (Time To Live)'.