Incremental Testing
Incremental testing is an integration testing strategy. In incremental testing you combine the next module to be tested with the set of previously tested modules before it is tested. In incremental testing, module integration is carried out in parallel with the module testing. The advantage of incremental testing is that the issues if any related to module interfaces are detected earlier and therefore are less costly to fix. A possible disadvantage is that you lose the ability to test the modules in parallel.
There is also one term known as Phased integration.
In incremental integration, only one new module is added, each time, to the partial system under test.
In phased integration, a group of related modules are added, each time, to the partial system under test.
Phased integration requires less number of integration steps compared to the incremental integration approach. However when failures are detected, it is easier to debug the system in the incremental testing approach since it is known that error is caused by the addition of a single module. [Reference]