DNSKEY is a DNS record type used by DNSSEC to publish the public keys a zone uses for signature verification. Resolvers and validating DNS servers read DNSKEY records to check whether DNS answers were signed by the right zone key and to build the chain of trust from parent to child zones.
In practice, DNSKEY matters because it sits on a security-critical parsing path. A validator must accept DNSKEY data from external domains, canonicalize it, compare it with related records, and verify signatures. That makes it a target for bugs: malformed DNSKEY-related input can trigger parser errors, memory corruption, or validation failures. Defenders rely on correct DNSKEY handling to block spoofed DNS responses, while attackers may try to abuse weak implementations by feeding hostile signed data to recursive resolvers.