In data visualization, what does a stacked bar chart primarily display?

A stacked bar chart primarily displays the proportions of different categories within each bar, where each segment of the bar represents a sub-category. This visualization allows viewers to easily see the total value of the main category while also understanding how that total is broken down into its constituent parts. For example, if you have a stacked bar chart showing sales by region, each bar represents the total sales for a region, and the segments within the bar show the contribution of each product to that total.

While other visualizations serve specific purposes, such as line charts for trends over time or bar charts for comparisons between groups, a stacked bar chart effectively highlights the composition of each category. By stacking the values, it emphasizes how much each sub-category contributes to the overall total, making it easier to grasp relative proportions at a glance. This characteristic distinguishes stacked bar charts from other chart types, reinforcing their utility in illustrating part-to-whole relationships.