A timeline is the presentation of a chronological sequence of events along a drawn line that enables a viewer to understand temporal relationships quickly. The term is also sometimes extended to mean a chronology that is tabular, year-by-year paragraphs or purely conceptual. Increasingly, timelines are illustrated in infographics combining text and graphic images for a better presentation.
Timelines are useful to document any type of development, providing an easy-to-understand history and helping viewers to understand past and ongoing trends. The tools are also useful for management tasks. In project management, for example, a timeline illustrates milestones, deadlines and other significant dates and events over the lifecycle of the project, clearly tying goals to specific dates. Annotations to the timeline can document actual progress.