What is the use of Black Box testing?

Black-box testing is a method of software testing that tests the functionality of an application as opposed to its internal structures or workings (see white-box testing).
This method of test can be applied to all levels of software testing: unit, integration, system and acceptance.
It typically comprises most if not all testing at higher levels, but can also dominate unit testing as well.

Blackbox testing is a technique where we test the functionality of an application.

Here we don't test the internal structure of an application like its coding.

Also, the application is tested by the end user where the user is not aware of internal structure of an application.

Black box testing is a testing technique where we can test a software functionality without knowing there internal coding structure. Black box testing. In black box testing we can perform functional, non-functional and regressional testing.

Examin the functionality of application or software without knowing internal structure or units

is a group of test cases og my program 

that can apply it or not 

 

is to test the cases that my programm applied