Agile model
Model that is flexible
Each incrementally delivered part is built through an iteration following each timebox in an agile paradigm.
Progress is measured in terms of developed and delivered capabilities when employing an agile paradigm.
Even if a project is cancelled in the middle, the agile methodology still leaves the customer with some useful code that may have already been placed into production.
The agile paradigm is more flexible since it allows for changes in requirements after the development process has begun.
Waterfall model
The waterfall paradigm is highly structured and follows a set of stages to gather requirements, analyse them, prepare SRS documents, design, code, and test them. The Waterfall model's phases are ordered in a certain manner.
Progress in the Waterfall approach is typically quantified in terms of the quantity of completed and reviewed artefacts such as requirement specifications, design documents, test plans, code reviews, and so on.
If a waterfall-model project is cancelled in the middle of development, the abandoned project leaves only a few documents behind.
The waterfall model is strict, preventing changes to requirements after the development process has begun.
