ZK proof (zero-knowledge proof) is like a 'no-spoiler guarantee'.
Imagine you have seen the ending of a movie, and you want to prove to your friend that you really know it, but you don't want to reveal the ending directly.
So you come up with a method that allows your friend to be 100% sure that you know the plot, but throughout the process, they won't be spoiled at all—this is the essence of ZK proof.
In scenarios such as blockchain, finance, and online accounts, ZK proof allows people to verify your qualifications or the validity of transactions without exposing passwords, amounts, or identity details, making it both secure and privacy-protecting.