The DS record is a specific DNS record that is used to secure the DNS (DNSSEC). It uses cryptographic keys to verify zones from the DNSSEC chain of trust.
What is DNSSEC?
DNSSEC is the solution to secure, otherwise unsecured DNS. It is a chain of trust that uses a combination of public and private cryptographic keys to authenticate each step of DNS resolving processes. Starting from the authoritative name server, going through each step on the way, and checking that the DNS records to see if they are truly coming from the authoritative name server for the zone.