Zero-Knowledge Proofs (ZKP) are a cryptographic approach that lets you verify the truth of a claim without exposing the underlying details. Think of it as proving you know a secret without ever divulging what that secret is. This tech is becoming fundamental in blockchain for privacy—users can confirm transactions, prove solvency, or validate smart contracts while keeping sensitive data completely hidden. It's basically the difference between showing your ID card and just proving you're above 18.