Alias-vs-CNAME-dns-records

The main differences between an alias record and a CNAME record in DNS are:

Functionality:

Alias: Can point to other record types like A, AAAA, or even another alias.
CNAME: Can only point to another domain name.


Root domain use:

Alias: Can be used on the root domain (e.g., example.com).
CNAME: Cannot be used on the root domain due to DNS standards.


Coexistence with other records:

Alias: Can coexist with other DNS records for the same name.
CNAME: Must be the only record for a given name (except for DNSSEC records).


DNS lookup:

Alias: The DNS resolver handles the mapping, returning the target's IP address directly.
CNAME: The client must perform an additional DNS lookup to resolve the target domain.


Performance:

Alias: Generally faster, as it requires fewer DNS lookups.
CNAME: May introduce slight delays due to additional lookups.


Flexibility:

Alias: Offers more flexibility in DNS configuration.
CNAME: More limited in its application