Functional Testing

Functional testing is a type of software testing that validates the software system against the functional requirements/specifications. The purpose of Functional tests is to test each function of the software application, by providing appropriate input, verifying the output against the Functional requirements .

Functions are tested by feeding them input and examining the output, and internal program structure is rarely considered (unlike white-box testing). Functional testing is conducted to evaluate the compliance of a system or component with specified functional requirements. Functional testing usually describes what the system does .

Sources:

Kshirasagar Naik, Priyadarshi Tripathy Software Testing and Quality Assurance: Theory and Practice. – Jojn Wiley, 2011 – 735