Functional testing is the stage of product development when software is tested for compliance. Functional testing can be manual or automatic. Functional testing software usually provides some input so that you can evaluate the output to see how the software works.

Functional testing is one of the types of testing aimed at checking the compliance of the functional requirements of the software with its actual characteristics. The main objective of functional testing is to confirm that the developed software product has all the functionality required by the customer.

Depending on the purpose, functional testing may be conducted:

Based on the functional requirements specified in the requirements specification. At the same time, test cases are created for testing (test cases), the compilation of which takes into account the priority of software functions that must be covered by tests. Thus, we can make sure that all the functions of the developed product work correctly with different types of input data, their combinations, quantities, etc.

Based on the business processes that the application must provide. In this case, we are not interested in the performance of individual software functions, as we are the correctness of the operations performed, in terms of system usage scenarios. Thus, testing in this case will be based on options for using the system (use cases).

The aspects described above are implemented using the following types and levels of testing:

• Modular (component).
• Integration.
• Systemic.
• Regression.
• Acceptance.

Ass well, there are many other types that provide complete and comprehensive testing of functional requirements for software.

Choosing the right functional testing tool for projects is key. Highly qualified testing professionals constantly update the set of tools used, as well as develop their own.