The Iterative development attempts to provide faster result, requires less upfront collection of information and offers more flexibility. The project is divided onto small parts and this allows the project team to produce and demonstrate results much faster. This in turn provides valuable feedback from the user, which helps avoid mistakes down the road.
Every iteration can be regarded as a separate Waterfall process. It is accepted that the output of the earlier iterations will not represent the final output and in many cases, the output of the earlier iterations may be thrown away, once the feedback from the user is received. The work put into the earlier iterations can save time and effort during the lifetime of the project and in the long term will lead to save in time.