Zone file
Also: DNS zone file, registry zone file
The authoritative list a registry publishes of every domain delegated in its top-level domain, together with the nameservers each one points at.
A zone file records delegation and DNSSEC signing, and nothing else: no registrant, no registrar, no registration or expiry date, and none of the domain's own A, MX or TXT records. That shape is what every tool built on zone data can and cannot answer.