zkApps represent a new way of building blockchain applications by combining privacy, efficiency, and affordability. They open up possibilities for use cases that require secure and private computations, such as identity verification, private financial transactions, and decentralized voting systems. By solving scalability and cost issues, zkApps provide a more user-friendly and sustainable approach to smart contract development.

zkApps, short for zero-knowledge applications, are a type of smart contract built on the Mina Protocol. They are powered by a cryptographic technique known as zero-knowledge proofs, specifically zk-SNARKs (Succinct Non-Interactive Arguments of Knowledge). This technology allows zkApps to prove that computations were performed correctly without revealing the underlying data, ensuring privacy and security.

Unlike traditional smart contracts that run entirely on the blockchain, zkApps take a different approach. They use an "off-chain execution" model, meaning most of the work is done outside the blockchain, and only a small proof is sent to the blockchain for verification. This approach includes managing the app's "state" (its current condition or data) either off-chain or with a combination of private and public states.