A timeline is a visual representation that organizes and displays a sequence of events or activities in chronological order. It provides a clear overview of the temporal progression and helps to understand the relationships between different milestones. Timelines are commonly used in various fields, including history, project management, education, and research, to present information in a structured and cohesive manner. They enable effective communication, facilitate comprehension, and offer a concise and engaging way to convey the flow of time and its impact on specific subjects.