A Stacked bar chart is just like a bar chart with a slight difference that each bar is further subdivided into 2nd categorical variable. These categories get divided into the bar as a part of the total. The different categories of different colors, stack upon each other in this type of graph.
Why do you need it?
The stacked bar chart helps us to compare not only the totals of the dataset but also the items that constitute that total. This gives our visualization a new dimension for analyzing the data at a higher granular level. This makes the analytical part more effective and time-saving.
What kind of data you can visualize with it?
When in your dataset there are two dimensions both based on one measure, then this graph is beneficial. Assume you have total sales of branches of a shop in different cities. By using this graph, you can see the total sales per branch as bars, and these bars divide further into items of shop like accessories, clothing, shoes, etc. This will help to see which item is the bestseller in which city.