Timelines are charts that show events in chronological order. There are many different kinds of timelines: some that use points, some that use lines like a line chart, some that use bars to represent spans. Many are interactive, with time scales that have adjustable ranges or can be scaled.

This may go without saying, but we’ll say it anyway: timelines are particularly useful for historical events. That’s because timelines use time series data to plot when events occurred along a line. This could be important battles in a war, biographical dates, events in the history of a company, or any data point with time associated with it.

Timelines are also used to show scientific data, such as the timeline of diseases and epidemics, geological timelines, or timelines of astronomical events.

Gantt charts are another form of timeline. They are seen in the everyday business world, generally used by project managers. Gantt charts show dependencies between tasks, as well as the sequence and duration of tasks.