A Timeline is a representation of every process w.r.t. time in chronological order. For using a timeline the data should contain dates. The dates define the time to spend on certain processes. We usually provide dates and processes on the X and Y-axis respectively.
Why do you need it?
We need a timeline to have a better view of all the tasks of a project in chronological order. In a timeline, every task has its priority, at what time it gets completed, how long it should continue, after this which task to perform.
What kind of data you can visualize with it?
A Timeline is best suited for time-related data. When you have start-end dates in your dataset and list of tasks to be performed on the other hand, then you can undoubtedly use a timeline to visualize your dataset. Examples of such types of datasets are construction projects, event planning, software development planning, etc. Workers can see progress, timeline, and schedule of every task from the chart.