Unit testing is a software testing technique where individual components or functions of a program are tested in isolation. The goal is to ensure that each part of the code behaves as expected, which helps identify bugs early in the development process. By focusing on small units of code, developers can verify that each piece works correctly before integrating it with other parts of the application. This practice is often automated, allowing developers to run tests frequently and efficiently. Unit tests serve as a safety net, making it easier to refactor code and add new features without introducing new errors. Overall, unit testing contributes to higher code quality and more reliable software.