Software Testing Levels

Testing has 4 levels:-
1.Unit Testing
2.Integration Testing
3.System Testing
4.Acceptance Testing

Unit Testing

Unit testing is a testing in which the individual unit of the software is tested in isolation from other parts of a program.Eg: Whitebox(Logic of the program) Test each module individually.

Integration Testing

Integration testing refers to the testing in which individual software units are combined and tested for a communication interface between them. Testing the code integrate 2 or more module ie, communicate between the modules.

3Types of integration testing:-

* Big Bang Testing
* Bottom Up Testing
* Top Down Testing

Big Bang Testing- Big Bang Testing is the type of integration testing in which every module is first unit tested in isolation from every other module. After that each module is combined all at once and tested.

Bottom Up Integration Testing- In Bottom Up testing, lower level modules are tested, then the next set of higher level modules are tested with the previously tested lower modules.

Top Down Integration Testing- In Top Down testing, higher level modules are tested and then the next set of lower level modules tested with the previously tested higher modules.

System Testing

Testing conducted on a complete, integrated system's compliance with its specified requirements.

Acceptance Testing

Acceptance testing is the testing conducted by the client/user to evaluate the system as per the business requirements.