What Is the Difference between a “First-Party” and a “Third-Party” Oracle?

A "first-party" oracle is one where the data source or the protocol itself runs the oracle node and provides the data directly to its own smart contracts. This is simple but reintroduces a single point of failure.

A "third-party" oracle is an independent, specialized service (like a DON) that provides data to multiple protocols. Third-party oracles are generally preferred for their decentralization, security, and independence from the consuming protocol.