Formal verification in hardware is a new way to make sure designs work correctly without needing input tests. It uses math to check all possible inputs and outputs automatically. This method guarantees 100% correctness, unlike simulation which relies on manual testing. Formal verification is especially useful for checking equivalence at lower levels of design complexity. Even though there are some challenges, it is a big help in dealing with today's complex designs. Tool vendors need to improve to handle large designs better.