Before your program is up and running and used by your customers, you need to test all the parts to make sure they are working correctly. Let’s find out what the features of program testing can be.

Why program testing
Testing is performed each time as soon as any changes in the source code of the program have been made. Any small change should be thoroughly tested for errors committed by the developers. The sooner the errors are found in the code, the more it will save the financial cost and time of the product, and also let your customers know that you are doing a quality job. None of your customers will be interested in stumbling upon functionality that isn’t working or isn’t working properly.

Functional testing
Functional testing is conducted to find out whether everything is feasible in the program and whether it works as it was intended. If your declared functionality is missing, the program will not be able to fulfill users’ tasks and they will not get the expected result.

Typically, functionality testing involves:

Determining the functionality running in the program
Step-by-step check of data input and output
Performance of prescribed actions for checking the correctness of functionality (test cases)
An analysis of the result of the functional program operation
Convenience and simplicity testing
Usability and simplicity testing is performed to find out whether the client is comfortable using the program. Usability testing is also called – usability, based on the English Usability Testing. It also includes elements of the functional testing, described above.

Testing the usability and simplicity of the program includes:

testing usability not only by testers, but also by other users
Elaboration of behaviors that coordinate functional testing
evaluation of the test results
Improving the usability and simplicity of the program based on the results
Interface testing
UI testing is performed to identify bugs in the appearance of the program and to fix them later.

Compatibility testing
Compatibility testing helps to find out whether the program can work together with other programs and devices.

Performance testing
Performance testing is performed to find out how well the program works under high loads on it by internal program subsystems, external services, number of user connections, etc. Usually for performance testing, high load is conducted on the program which should lead to malfunctions in its functionality. Developers then eliminate bugs in places that are most susceptible to load.

Security testing
The security testing of a program is done to find out the vulnerabilities that can become a tidbit for intruders. Timely detection of security bugs will help protect the program from unauthorized access and actions of other malicious programs.

Security testing includes:

verification of safe and secure data transmission
verification of access to internal program parts
verifying access to user data
Terminating a session once user activity has ended or the program has been shut down
Prohibition of arbitrary downloads and file saving
Checking user error handling.
At last, we have considered the most basic steps of testing programs. Each type of testing is aimed at making the program as good as possible for the user.