If you are debating about hiring a professional software testing company, to get your programs checked and verified, you should know what they do exactly.
Here is what they do
They have a team of engineers who are specifically designated to test the software that are created by the company. These engineers use the following methods to ensure the quality of the final product:
Black Box Testing
This is a test that is performed without any knowledge about the program in question. The engineer is informed about how the program is supposed to work and they test if it indeed works in that way. They are not aware of the end result or what conclusions are formed when the program is run. Hence the programmer and the tester work independently and are not even aware of each other. There is no need for them to meet and discuss about the software. This type of testing is done for small time software that requires jut a basic check.
Whit Box Testing
Also known as glass box testing, the tester needs to know about the program and incorporated this information with the programs’ internal structure to get the desired results. In order to check if the software works as intended, the tester used his knowledge about the program to check if it is working properly. This type of testing is performed when one is searching for internal errors in already existing programs. When the tester knows how it works, it makes it easier to not only narrow down the search, but fixing it also easier.
Gray Box Testing
This is nothing but the combination of the above two. This is used when there is limited knowledge about the system. Since the tester does not know much about the system, he is forced to use black box testing methods to find problems in the system. He then uses the limited knowledge to fix the problems.