Here we break the whole module into chunks. In first iteration I will only work on login page and home page.

When that development is completed and testing is done, only then I will go to second iteration. So if business has 50 requirements, then first 25 requirements are developed and tested in first iteration, so only after first 25 iterations are tested and certified the second iteration is run for the next 25 resin iterative model testing starts after some development is completed like 30 percent not as waterfall model where 100 percent development is complete.