This practice focuses on verifying individual functionalities of a software application, validating that each component operates as designed. It encompasses examining a specific aspect of the software and ensuring that it fulfills its intended purpose. For example, if an application has a user authentication module, this would involve confirming that users can successfully log in with correct credentials and are denied access with incorrect credentials.
Its value lies in ensuring that all parts of the software contribute positively to the overall user experience. Thorough validation of these discrete elements reduces the risk of integration issues and contributes to a more robust and reliable final product. Historically, as software complexity increased, the need for focused validation methods to prevent cascading errors became evident, leading to the establishment of these practices as a vital stage in the software development lifecycle.
