A phase, or stage, refers to a distinct period in a process or development characterized by specific features or activities. Phases are often used to describe the progression of projects, life cycles, or natural phenomena, such as the moon phases, which include new, waxing, full, and waning. In project management, phases help organize tasks and milestones, making it easier to track progress. Common phases include initiation, planning, execution, and closure. Each phase has its own objectives and deliverables, ensuring that the project moves forward in a structured manner.