A Zero-Knowledge (ZK) proof is a system that allows a party to prove their possession of certain information without revealing the information itself.

A Zero-Knowledge (ZK) rollup is a Layer-2 scaling solution for blockchains, particularly designed to improve scalability and reduce transaction costs.

A ZK-SNARK is a cryptographic technique used to prove possession of certain information without revealing that information itself.

A ZK-STARK is a cryptographic proof system used in blockchain and cryptocurrencies designed to provide a way for users to prove the validity of certain information or computations without revealing any of the underlying data.