zk-SNARK stands for “Zero-Knowledge Succinct Non-Interactive Argument of Knowledge.” It allows one party to prove to another that they know a value without revealing the value itself and without any interaction after the initial setup.A zk-SNARK circuit is a mathematical representation used to verify these proofs. Think of it as a series of logical operations or constraints that define how inputs relate to outputs. The circuit is designed to express a specific computation, which can be related to transactions or other processes.When a party wants to prove they have valid information (like being eligible for a transaction) without revealing the details, they use zk-SNARKs. The circuit checks that the inputs meet the defined conditions while keeping the inputs confidential. This technology enhances privacy and scalability, enabling secure transactions or data verification while minimizing the amount of information shared. It is particularly useful in blockchain environments where maintaining confidentiality is crucial.