Use the correct relative name
If your DNS dashboard manages example.com, a host field such as shop may represent shop.example.com. Some interfaces accept the full hostname instead; follow the provider's instructions and inspect the resulting record name.
Choose a record type suited to the destination. An address record points a hostname to an IP address, while an alias-style record can point to another hostname where the DNS provider supports it. Do not use a type just because its label looks similar.
Verify the subdomain resolves as intended
After saving, query the authoritative answer for the full hostname and check the exact type and value. If the subdomain serves a website or mail service, complete any separate verification or certificate setup that service requires.
Avoid creating conflicting records for the same name and type. If you no longer need the subdomain, remove only its associated records after checking whether another service or team still depends on them.