Formal methods are mathematical techniques used in computer science and software engineering to specify, develop, and verify systems. They provide a rigorous framework for ensuring that software behaves as intended, reducing the likelihood of errors and improving reliability. By using formal languages and models, developers can analyze complex systems systematically. These methods often involve creating formal specifications that describe system behavior and properties. Tools and techniques, such as model checking and theorem proving, are employed to validate these specifications against the actual implementation. This approach is particularly valuable in critical systems, such as those found in aerospace and medical devices.