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 and documentation, making it highly structured and predictable. This approach is often contrasted with more flexible, iterative methodologies like Agile.
Developers should learn Waterfall for projects with well-defined, stable requirements and low uncertainty, such as government contracts, safety-critical systems, or large-scale infrastructure where regulatory compliance is key. It's useful when changes are costly or disruptive, as it provides clear milestones and documentation, but it's less suitable for dynamic, user-facing applications where requirements evolve frequently.