DNS and DoH Glossary

This document explains common terms related to DNS and DNS over HTTPS.

Basic Terms

DNS (Domain Name System)

  • Domain Name System
  • System that converts human-readable domain names into IP addresses
  • One of the fundamental infrastructures of the internet

DoH (DNS over HTTPS)

  • DNS over HTTPS
  • Encrypts DNS queries and responses using the HTTPS protocol
  • Provides better privacy protection and security

DoT (DNS over TLS)

  • DNS over TLS
  • Encrypts DNS communication using the TLS protocol
  • Similar to DoH but uses a different protocol

Technical Terms

Recursive DNS

  • Recursive DNS server
  • DNS server responsible for complete domain name resolution
  • Queries other DNS servers to obtain complete answers

Authoritative DNS

  • Authoritative DNS server
  • Stores DNS records for specific domains
  • Provides definitive answers for domain names

DNS Resolver

  • DNS resolver
  • Client software that performs DNS queries
  • Can be operating system, browser, or standalone application

DNS Query

  • DNS query
  • Request sent to a DNS server
  • Contains the domain name to query and query type

DNS Response

  • DNS response
  • Answer returned by DNS server
  • Contains query results and related information

Security Terms

DNSSEC

  • DNS Security Extensions
  • Provides data integrity verification for DNS
  • Prevents DNS responses from being tampered with

ESNI

  • Encrypted Server Name Indication
  • Encrypts SNI information during TLS handshake
  • Provides additional privacy protection

DNS Leak

  • DNS leak
  • DNS queries transmitted through unencrypted channels
  • May expose user privacy

Performance Terms

DNS Cache

  • DNS cache
  • Temporary storage for DNS query results
  • Improves DNS resolution speed

DNS TTL

  • Time To Live
  • Valid time for DNS records in cache
  • Controls DNS record update frequency

DNS Round Robin

  • DNS round robin
  • Returns multiple IP addresses for the same domain name
  • Implements load balancing

HTTPS

  • Hypertext Transfer Protocol Secure
  • HTTP protocol based on TLS
  • Provides encrypted communication

TLS

  • Transport Layer Security
  • Provides encryption and authentication
  • Protects data transmission security

HTTP/2

  • Second version of HTTP protocol
  • Supports multiplexing
  • Improves transmission efficiency

Next Steps