The subdomain is holding a PHPmyadmin app.
should Type: www be used with hostname: db.domain.com
and can it also be used with type: www hostname: domain.com
Thank you, have read conflicting options
If you need to add a www for your domain - domain.com you can do both, e.g adding a CNAME record for www or just create an A record for db.domain.com
If you want to have a db.domain.com accessible ...