Functional Testing and Non-Functional Testing

Software testing is a process that verifies and validates an application to and provides a robust, error-free, functionally correct, secure, and high-quality end product. Ideally, the testing process should be efficient, cost-effective, and resource-friendly. To achieve that, it is imperative to combine a variety of testing techniques to formulate the testing strategy based on the “Operability” and “Efficiency” of the software under test. “Operability” parameter is taken care of by functional testing and “Efficiency” is taken care of by non-functional testing.

What is Functional Testing?

Functional testing verifies and validates the functionality of the application against the specified requirements. It ensures that the application adheres to all the approved specifications and works as per the expectations. It tests the functional accuracy, interoperability of subsystems, and compliance with pre-defined standards in the context of functional and business requirements. For example, the mandatory fields on a user registration page are filled or not. If filled, does the submit button perform the desired action, etc.

What is Non-functional Testing?

Non-functional testing validates the readiness of the application by testing its behavior under different conditions. It tests for stability, durability, security, performance, etc. For example, what if the system works fine when a limited number of users try to access it. But what will happen on extremely high traffic days? Will the system slow down? Will it crash? Or it starts behaving abnormally. All such conditions are tested during non-functional testing. Read for more information: Key differences between Functional Testing and Non-Functional Testing