WaterFall Model: This is a flow based model, in which u 
pass every phase once, and can not go back to that phase 
again. That is why, it is used rarely now a days.

Drawback: If there is nay change in requirements, then u 
can not make any chnages in  requirements.

Iterative Model: In this u can come back to previous 
phases, and make the changes accordingly. In this we 
revieved a final output product at the end of the SDLC.

Prototype Model: Here, we recieved Prototypes of the 
product, before the final release. We relaese 4-5 Protypes 
with some diffrences b/w them, and take client opinion, and 
modifies the final Product, as per client suggestions.

Waterfall model: It includes all phases of SDLC.The 
drawback is once the requirements request made 
freezed,changes can't be done during any phase. 

Iterative model: We can change requiremnts at any phase, 
but the problem is all the phases of SDLC can take place 
again.

Prototype model: We can change requirements before design 
and coding can proceed.In this model, prototype is 
developed based on the currently known 
requirements.Development of prototype undergoes design, 
coding, testing, which give client an actual feel of the 
system. Prototype is a model which looks exactly like SDLC