It is a process where all the units of a system are 
integrated consequtively and integrated in step by step 
process by incrementing the levels of testing at one end to 
other end.

it is a process were all the units of a system are 
integrated and testing is carried out on this...

Incremental Integration testing is the testing of the 
application by adding new functionalities to an application.
It is a continous testing activity in which the application 
is tested by adding new functionalities. These type of 
testing is performed by programmer, software engineer, test 
engineers.

It is a combination of Incremental and Integration 
Testing,wherein in every subsequent build,more requirements 
are added and then builds are integrated and then tested as 
an Integrated whole.