This white paper presents a structured comparison of two foundational project management methodologies—Waterfall and Agile. It examines Waterfall’s linear, phase-based approach and contrasts it with the adaptive, iterative nature of Agile, shaped by the principles of the Agile Manifesto. By exploring key frameworks, practical applications, strengths, limitations, and adoption challenges, the paper equips organizations with the insights needed to align their project management strategies with dynamic business environments and evolving market demands.