Explain approaches used in executing Integration testing?

Below image can be used to summarize the approaches used in executing integration testing:

There are two approaches, used to perform Integration testing, the first being

1- Big bang approach: Under this approach all the modules of the application or different components of the system are integrated with each other and tested as a whole validating both the specifications as well as the complete business flow of the application.

2- Incremental Approach: In this process, one module is integrated with another module and tested. If this works fine, the next piece of module is attached to existing structure and validated. It is during this approach that the concept of Driver and Stub may come into the picture.

Incremental approach is further divided into two categories, Top Down and Bottom Up approach and depending upon them, the dummy code used in integration is called as Driver or stub.