DNS translates domain names to IP addresses:
Browser checks local cache
OS checks its cache
Query recursive resolver (ISP or public like ...)
Resolver queries root servers → TLD servers → authoritative servers
IP returned and cached at each level
TTL (Time To Live): How long to cache the result.
Record types:
- A: IPv4 address
- AAAA: IPv6 address
- CNAME: Alias to another domain
- MX: Mail servers
DNS is a potential bottleneck. Use appropriate TTLs for your use case.