The Stream Chart (Stream Graph) is the representation of data in which the data is not represented along a fixed, straight axis. Here, the values have a representation along a varying central baseline. That’s why there is no corner in the chart, and the edges are round, which gives it a nice impression of flow.
Why do you need it?
A Stream chart helps to show the relative proportion of the whole data. These are helpful to show the changes in different categories over time when there are many categories, and each category starts and stops differently. The height of each stream shows the changes, and the length of the stream shows the duration to which the change has been there.
What kind of data you can visualize with it?
Stream graph works well when there is no doubtful pattern in the data. That means the data should be accurate and in a proper pattern. If the proportion of each category remains more or less the same at times, then it will be quite difficult to represent as the minor changes or variations would be difficult to observe.