Testing the data flow or the interface between the modules is known as integration testing.
Types of Integration Testing:
Incremental Integration Testing.
Non-Incremental Integration Testing.
Incremental Integration Testing
When there is clear relationship between the modules then we go for incremental integration testing.
There are two approaches for incremental integration testing:
Top down approach.
Bottom up approach.
Top down approach
In top down approach we incrementally add the modules from top to the bottom and check the data flow in same order.
Bottom up approach
In bottom up approach we incrementally add the modules from bottom to the top and check the data flow in same order.
When there is no clear relationship between the modules then we go for Non-Incremental Integration Testing.
Since the data flow is not clear between the modules we hit on each module and check for data flow so it is also known as big bang method.