What is the difference between a bar graph and a histogram?

The distinction that a bar graph represents categorical data with gaps between the bars, while a histogram represents continuous data with the bars touching, accurately describes the primary difference between these two types of visual data representations.

Bar graphs are designed to illustrate the frequency or frequency distribution of distinct categories. Each category is separated by a gap, which emphasizes that the categories are discrete and do not flow into one another. This separation indicates that the data points are independent of each other.

In contrast, histograms are used to display the distribution of continuous data. In a histogram, the data is grouped into bins or intervals, and the bars are adjacent without gaps. This touching of bars signifies that the intervals are continuous and signify a range of values, reflecting how the data is distributed across those ranges.

This distinction is critical because it informs the viewer about the nature of the data being represented—categorical data versus continuous data— and helps in the correct interpretation of the visualized information. Understanding these differences is foundational in data analysis, particularly in identifying the appropriate graphical representation for data types in statistical contexts.