The integration Testing is doing for integrated modules. So 
first of all we required an integrated application to do 
the integration testing.

Here we have to check wether the integrated modules are 
working properly or not. This can be do through the 
integration test cases.

For example Creating a user account and login to the system 
are two modules.

Here u can see the Create User is a module and Login user 
is another module. So First we create a user then with the 
new username and password we logon to the system. If it is 
working as per the expectation then the test is pass.

Is it Clear?