V Model

V-V Model, V-V stands for Verification and Validation.
 In V-Model verification and validation is done simultaneously. This model has partial downward flow. In each and every phase of SDLC testers also review requirement document and proceeds to next phase. So quality of product will be high when compared to other models.

Prototype Model

Prototype Model is used when customer has no clear idea on requirements of application. Business Analyst gathers all requirements from customer and proposes somemore requirements according to domain specification and shows a blue print of application.

Spiral Model

Spiral Model is used to develop large and complex projects. Spiral model combines the features of Prototype Model and Waterfall Model. It is similar to Incremental model.
Spiral Model is designed in spiral form and divided into 4 phases. They are:

Incremental Model

Any project developed with Incremental model have multiple iterations of builds which are incremented one by one to complete it. In Incremental model a project is divided into many small builds and develop builds one by one and delivery is done for each small build.

Waterfall Model

Waterfall Model is a traditional sequential model in which development of each phase is seen steadily downwards(like water flows from top to down). We cannot change requirements easily because of its downward flow. New requirements can be added in next cycle only. Customer interaction is very less in waterfall model.