DNS

The DNS (Domain Name System) service is essential for accessing the internet. When the IP address of a website is unknown, the DNS converts the domain name into an IP address and vice versa.

13 root name server in the world, but replicated !

TLD (Top Level Domain)

TLDs are the extensions at the end of a URL that uniquely identify a FQDN (Fully Qualified Domain Name), which is the complete domain name (including the extension).

Types of DNS Records

• A – Matches an IPv4 address with a domain name.
• AAAA – Matches an IPv6 address with a domain name.
• CNAME – An alias that links a name to another, usually longer or more complex name.
• MX – MX (Mail Exchanger) records link a given name with the mail server for sending emails.