Definition
Agile and Waterfall represent two fundamental approaches to project management, differing primarily in their structure and flexibility. Waterfall follows a linear, sequential process where each phase must be completed before the next begins, emphasizing upfront planning and documentation. Agile, conversely, employs an iterative and incremental approach, breaking projects into smaller cycles or sprints that allow for continuous feedback and adaptation. This difference matters significantly in practice, as Agile is better suited for projects with evolving requirements, while Waterfall excels in environments with stable, well defined needs. For instance, developing a new software feature often benefits from Agile's adaptability, whereas constructing a physical building typically aligns with Waterfall's structured progression. A common point of confusion is viewing them as mutually exclusive, when in reality, hybrid approaches can combine elements of both. Understanding these methodologies is crucial for project success and is tested on exams like the PMP and PMI-ACP.