What is DNS?

DNS stands for Domain Name System. It translates readable domain names such as bajorat-media.com into technical IP addresses that servers use on the internet. Without DNS, users would need to enter numeric or alphanumeric addresses instead of domains to reach websites, email servers or other services.

ICANN describes DNS as a system that makes the internet easier to use by connecting text-based domain names with IP addresses: ICANN: The Domain Name System.

How does DNS work?

When a browser opens a domain, it first asks a DNS resolver for the matching address. If the answer is not already cached, the request is resolved through several levels: root name servers, top-level domain name servers and finally the authoritative name server for the domain.

The authoritative name server returns the relevant DNS records. The browser can then contact the correct web server and load the website.

Important DNS records

Website owners commonly deal with these records:

• A and AAAA: connect a domain to IPv4 or IPv6 addresses
• CNAME: points one host name to another host name
• MX: defines mail servers for receiving email
• TXT: often used for verification, SPF, DKIM or DMARC
• NS: defines which name servers are responsible for a domain

DNS affects websites, email, subdomains, tracking verification, CDN integrations and hosting.

Why DNS matters in website projects

During relaunches, hosting migrations or domain moves, incorrect DNS settings can make websites unreachable, break email delivery or prevent certificates from working. DNS changes should therefore be planned, documented and tested.

DNS is closely connected to web hosting and WordPress hosting, SSL certificates, subdomains and CDNs.