1. Waterfall Model :-
This is the first software development model. waterfall model is the linear sequential model in which all the phases works in a sequential manner. The output of the previous phase is the input for the upcoming phase. But we cannot go back to the prior stage to change requirements. There is no overlapping between the phases of the software development. This model takes less time to develop and very easy to understand.
2. Iterative Waterfall Model :-
This model is used to overcome the disadvantages of waterfall model. Iterative waterfall model provides the feedback path for all the phases to its previous phases but there is no feedback path for feasibility study. So if customer’s requirement is not clearly specified then we cannot alter the requirements if we come to the software design phase.
3. Agile Model :-
Agile model is the process which divide tasks into small iterations, or segments.This model is the combination of iterative and incremental model. Agile Method break the software product into small incremental modules and this model and this model completes the project in iterations. Each iteration contains planning, designing, coding, testing, maintenance of the software.
4. Spiral Model :-
The spiral model is the integration of waterfall model and iterative model. This model contains four phases that is planning, risk analysis, development & testing and evaluation. After completing each iteration, customer evaluates the software product and give feedback. On the basis of customer feedback, developers starts the next iteration of the software development.
5. Prototype Model :-
A prototype is created and tested in the prototype model. this prototype is send to the customer and takes reviews from them. If the client is satisfied with the prototype then developer starts implementation based on the design phase. If the client is not satisfied then prototype is again build and tested. The software product will be more efficient an free of bugs.
6. V Model :-
As name suggests, V model completes the software development process in V shape. V model is known as verification and validation model which is the extension of the waterfall model. Each development stage is tested through the testing phases associated with every phase. In this, verification is the phase done on the left side and validation phase is done on right side.
7. RAD Model :-
RAD model is the rapid application software development model. This process is based on the iterative and prototype model. In RAD model, whole project breaks down into small segments or modules. when all the modules are completed then integrate to make a final software product. This process contains four phases that is requirement analysis, customer evaluation, construction and cut-over.
