DNS records

The common types: an A record points a name at an IPv4 address and AAAA at an IPv6 address; a CNAME makes one name an alias of another (www pointing at a host's address, for example); MX records name the servers that receive email; TXT records hold text, used to prove you own a domain and for email rules such as SPF, DKIM and DMARC. NS records name the nameservers, and CAA records say which certificate authorities may issue certificates for the domain.

Every record has a TTL that sets how long others may cache it. The bare domain (example.com, called the apex) cannot be a CNAME under the standard rules, so DNS hosts offer an ALIAS or ANAME record, or CNAME flattening, instead. When you connect a site to Vercel or Netlify, or an email service, the provider lists the exact records to add.