Functional testing is done to verify all the functionality of a product. Functional testing is a type of testing which verifies that each function of the software application operates in conformance with the requirement specification. This testing mainly involves black box testing and it is not concerned about the source code of the application. During functionality testing, core application functions, text input, menu functions, and installation and setup on localized machines are checked. It becomes more effective when the test conditions are created directly from user/business requirements. Functional testing is an important part of quality engineering.
All testing strategies should include functional testing at their core. Functional tests are critical to ensuring that a product or feature will function appropriately for users. Functional testing is only one of many activities that collectively comprise a comprehensive testing strategy. However, depending on the requirements and expectations of your company, different testing activities. Moreover, functional testing also checks the software for usability, such as by ensuring that the navigational functions are working as required.
In the view of the quality engineering professionals, functional testing can be divided into two segments, one is requirements-based testing, this testing technique contains all of the functional specifications that eventually form a basis for all the test cases written, another one is business scenarios-based testing, this particular technique contains information about how business perceives the system and will pave way for relevant test cases.