What does functional testing verify?

Functional testing is a type of software testing that focuses on verifying that a system meets its specified requirements and performs its intended functions correctly. This type of testing assesses the actual functionality of the software against the expected outcomes defined in the requirements documentation.

When conducting functional testing, testers typically validate that each feature works as expected and fulfills the needs of the users. This may involve testing user inputs, business logic, and outputs to ensure that they align with the defined requirements. Achieving this goal is essential for ensuring that the software provides the intended value to users.

Other answer choices are related to aspects of software quality but do not specifically capture the core emphasis of functional testing. For example, while security and navigation can be significant elements of software evaluation, they fall under different testing categories, such as security testing and usability testing, respectively. Similarly, verifying that a software system is free of bugs relates more to quality assurance and testing methodologies like regression or unit testing, rather than to the functional testing phase which concentrates on function and requirements alignment.