What defines the Waterfall approach in software development?

The Waterfall approach in software development is characterized by its linear and sequential structure. In this model, each phase of the development process must be completed entirely before the next one begins. This means that requirements are gathered first, followed by a thorough design phase, implementation, testing, deployment, and maintenance, with each phase building upon the results of the previous one. This rigid structure helps to ensure that the project progresses in a systematic way, making it easier to manage and document each step thoroughly.

In contrast to other models, such as Agile, which allow for overlap and iteration throughout the development process, the Waterfall approach does not support revisiting earlier phases once they are completed. This can be beneficial for projects with well-defined requirements where changes are minimal, as it ensures focus and clarity at each step.

While methodologies that prioritize user feedback and rapid prototyping have their merits, they do not align with the structured and sequential nature of the Waterfall model. The emphasis on completing each phase before moving on is what fundamentally defines this approach.