What is DNS?
DNS stands for Domain Name System. It’s like a phonebook for the internet, translating human-readable domain names (like google.com) into IP addresses (like 142.250.189.174) that computers can understand.
How does DNS work?
- Domain Name Registration: When you register a domain name, it’s added to a global database.
- DNS Records: Your domain name is linked to an IP address through DNS records (e.g., A records, CNAME records, etc.).
- DNS Query: When you enter a URL or send an email, your device sends a DNS query to a DNS resolver (usually provided by your ISP or operating system).
- DNS Resolution: The DNS resolver asks multiple DNS servers (in a hierarchical order) to find the IP address associated with the domain name.
- IP Address Retrieval: Once the IP address is found, it’s returned to your device, allowing you to access the website or send the email.
DNS is a crucial system that enables us to access online resources using easy-to-remember domain names instead of difficult-to-remember IP addresses!
Types of DNS Records
- A Record (Address Record): Maps a domain name to an IP address (e.g., google.com → 142.250.189.174).
- CNAME Record (Canonical Name Record): Maps an alias or subdomain to the main domain name (e.g., xyz.com → example.com).
- MX Record (Mail Exchanger Record): Directs email to a mail server.
- NS Record (Name Server Record): Identifies the name servers responsible for a domain.
- PTR Record (Pointer Record): Maps an IP address to a domain name (reverse DNS, e.g., 142.250.189.174 → google.com).
- SOA Record (Start of Authority Record): Specifies the DNS server responsible for a domain and other domain-related info.
- TXT Record (Text Record): Contains text information about a domain (e.g., SPF records, DKIM keys).
- SRV Record (Service Record): Specifies the location of services like VoIP or instant messaging.
- AAAA Record (IPv6 Address Record): Maps a domain name to an IPv6 address.
- CAA Record (Certification Authority Authorization Record): Specifies which CAs are allowed to issue SSL/TLS certificates for a domain.
These records work together to ensure that your domain name is correctly linked to your online resources, like websites and email servers!