1.Waterfall model is a document driven process. While spiral model does not requires the documents2.Waterfall model is best suited for large projects. Spiral model is best suited in case of complex projects.3.Accommodating changes in the middle is difficult in waterfall model. On the other hand, accommodating changes in requirement is easy in a spiral model.4.The phases of waterfall model are:Requirement Gathering and Analysis PhaseDesign PhaseCoding PhaseSystem Integration PhaseTesting and Debugging PhaseDelivery PhaseMaintenance PhaseRead more at Buzzle: http://www.buzzle.com/articles/comparison-between-waterfall-model-and-spiral-model.htmlThe phases of spiral model are: Planning PhaseRisk Analysis PhaseEngineering PhaseCoding and Implementation PhaseEvaluation Phase5.While in the spiral model, the customer is made aware of all the happenings in the software development, in the waterfall model the customer is not involved. This often leads to situations, where the software is not developed according to the needs of the customer. In the spiral model, the customer is involved in the software development process from the word go. This helps in ensuring that the software meets the needs of the customer.6.In the waterfall model, when the development process shifts to the next stage, there is no going back (means we cannot revisit the previous phase of development]In the spiral model, one can revisit the different phases of software development, as many times as one wants, during the entire development process7.Waterfall model is sequential in nature ie if a bug is found or an error is incurred for a preliminary reason, we need to start from the scratch again. Whereas, Spiral model is spiral in nature ie every prototype is tried and tested and hence the chances of find errors at later stages are very rare8.Waterfall model is simple to implement and spiral model is comparatively difficult to implement9.In waterfall,there are minimal risks of not meeting budget or schedule but in spiral model,there are higher risks of not meeting budget or schedule10. Waterfall model is applied in same manner for every application whereas spiral model is applied differently for each application11.The amount of resources required to implement this model is very minimal in waterfall model whereas the amount of resources required for software development using spiral model are high12.Waterfall model implementation does not require expertise whereas Spiral model requires highly specific expertise in risk analysis13. Waterfall model is suited for small projects but spiral model doesnt suits for small projects14. In waterfall model,,software is produced at final stage (at the end) in the software life cycle whereas in Spiral model, software is produced early in the software life cycle15.Small changes or errors may cause lot of problems in software development in watrefall model ...in spiral model, small errors will cause negligible harm to software development process

More distinguishing points---------------------------------------http://efficientprograms.blogspot.in/2013/07/spiral-model-vs-waterfall-model-agile.html

References----------------http://www.buzzle.com/articles/comparison-between-waterfall-model-and-spiral-model.html

http://www.sdlc.ws/difference-between-spiral-and-waterfall-model/

http://blog.nawaratne.com/2011/03/comparison-of-waterfall-and-spiral.html