Waterfall
Waterfall is a linear, sequential software development methodology where each phase (e.g., requirements, design, implementation, testing, deployment) must be completed before the next begins, with minimal overlap or iteration. It emphasizes thorough upfront planning, documentation, and a structured approach, often used in projects with well-defined, stable requirements. The methodology is named for its cascading flow, resembling a waterfall, where progress flows steadily downward through the phases.
Developers should learn Waterfall for projects with fixed requirements, regulatory compliance needs, or in industries like aerospace or healthcare where predictability and documentation are critical. It is useful when scope is clear from the start, changes are costly, and stakeholders prefer a rigid timeline and budget. Understanding Waterfall helps in contrast with agile methodologies and in environments where traditional project management is still prevalent.