Plain meaning
Start with the shortest useful explanation before going deeper.
A testing methodology where developers define properties (invariants) that must hold true for all valid inputs, and a test framework generates random inputs to attempt to falsify those properties. Unlike unit tests that check specific examples, property-based testing explores the input space stochastically. For Solana programs, properties might include 'total token supply never changes during transfers' or 'only the authority can modify the config account.' Tools like Trident and proptest support this approach.