The waterfall software development model is the simplest of it's type as it states that the design and creation process of a website can be of a linear order. The order is very strict
e.g. once the analysis is done only then can the requirements specification be done, then once the requirements specification is done then the design can begin and so on.
Through following the waterfall so strictly it can lead to a project being completed within its time limit every time. However it does have it downfalls. The waterfall allows you to establish a solution early by effectively freezing off each section before starting another. However this creates a problem when system requirements, user needs or design purpose change as you can't go back a stage to change the design. The waterfall can lead to the ultimate disaster- the system might become irrelevant.
To make the waterfall work for you you need highly skilled designers that are gifted with foresight to enhance the system but it will reach a point when it won't be able to be enhanced any longer. In my opinion the waterfall would be better suited to building a structure because it will have clearer objectives and and relatively stable architecture whereas the purpose of a website could change instantaneously.
In comparison the whirlpool is better design as it keeps in mind that the system requirements may change without warning so it focuses on a select few, important set of requirements in order to provide a basis for the project. The riskiest and most convenient hurdles are tackled first so that it can be predicted whether the project will become to expensive or threatening. This leads to more stable structures.
The most useful part of this model is that it allows you to work on more than one section at once, such as design and analysing or coding and maintenance.
The whirlpool can be a useful strategy when it comes to website design because it allows you to come back to areas of the design process to make modification whereas the waterfall will only allow you time to go through once.