Difference between Waterfall Model Vs. V Model

Waterfall Model	V Model
Once 1^st Phase over and Process goes to next Phase then we can not revert back to 1^st phase.	If 1^st phase over and changes occurred in that phase and we can revert back to that process by paying some amount.
Simplicity of Waterfall model is simple.	Simplicity of V model is Intermediate.
Cost of Waterfall model is Low	Cost Of V model is expensive.
Flexibility of Waterfall Model is rigid	Flexibility of V Model is little Flexible.
Waterfall Model move in Linear Process.	V Model Do not move in Linear Process.
Guarantee of success of waterfall model is low.	Guarantee of success of V model is high.
In Waterfall Model, Testing Phase start after the Development Phase.	In V Model , Testing Phase start with Development Phase.
Waterfall Model is Continuous process.	V model is Simultaneous Process.
It is less used now a days in software engg.	It is widely used in software Engg.
In Waterfall Model, the defects are identified in the testing phase.	In V model, the defect are idenitified from the initial phase.
Waterfall Model is used when the requirements of the customers are fixed.	If customer requirement keep changing then V model is better alternate model.
Making changes in the Software in the waterfall model is a costly.	Making changes in the Software in v model is comparatively cheaper.
Software made in waterfall model has most defects compared to one made in v model.	Software made in v model has lesser defects compared to one made in Waterfall model.