Before we start to differentiate the two, we first need to understand what these terms mean and following which the difference can be explained with ease.
This is a type of test that checks whether all the functions that the application is performing just as they are required to or no. The prime focus is on testing the black box and not on the application’s main source code. The primary process of testing involves feeding the application with appropriate inputs and correspondingly finding the outputs, further which these outputs received would be compared to the expected outputs. Under this testing technique, several things are checked, such as Database, client applications, user interface, and API.
This testing could either take place manually or could be automated. A lot of platforms can help you with the testing of these apps.
Non Functional Testing
For all the factors that are not testing under functional testing, there is non-functional testing. This sort of software testing usually takes place to check the non-functional requirements of any application. Its motive is to see if the behavior of the following system is changing or remains the same. In case we have to give an example of this, we could say: it would check, at a particular time, what many people can log in to the software.
Effecting the Client satisfaction this type of testing is also considered extremely important and equal to Functional Testing
The Main Difference between the two testings
There are several parameters based on which the two types of testing can be compared. Let’s go through them one by one.
1. Objective: The main objective of Functional testing is to check the actions of the software, whereas for non-functional, it is to check the performance.
2. Execution: Functional testing takes place before the non-functional testing and the other after.
3. Focus area: Functional is based on the requirements of the customer, and non-functional deals with the expectations.
4. Manual testing: Manual testing is functional is fairly easy, and in nonfunctional testing, it is considered extremely hard.
5. Functionality: Functional Testing describes what the product can do, and non-functional describes the working of the product.
6. Requirement: The requirements of functional testing can be easily defined, whereas it is extremely difficult to define the main requirements in non-functional testing.
7. Testing types: The common kind of examples that can be considered under functional testing are smoke testing, integration testing, unit testing, globalization, user acceptance, localization, and others. Whereas for non-functional testing, they can be Load testing, Performance testing, Volume Testing, Stress testing, Portability testing, Compliance testing, usability testing, and some others.
8. Usage: Functional Testing validates the overall behavior of the application, and non-functional testing helps in validating the complete performance of the given software.
9. Test Case Example: One of the case examples for functional testing could be checking the login functionality of the system, and an example that we can consider for the non-functional testing is say testing if the dashboard loads in 2 seconds or not, here you are basically testing the performance of the dashboard. This explains the basic difference between the two testings.