What is the correct definition of a histogram?

A histogram is correctly defined as a graphical representation of the distribution of numerical data. This is accomplished by dividing the data into intervals, known as bins, and then representing the frequency of data points that fall within each bin using bars. The height of each bar corresponds to the number of data points in that interval, allowing for visual insight into the underlying frequency distribution of the dataset.

This ability to show how data values are distributed across different ranges makes histograms particularly useful for interpreting the shape of the data, such as whether it is skewed, uniform, or bell-shaped (normal distribution). In contrast, other options do not accurately capture the essence of a histogram; a line graph represents functions and trends over time, a circular diagram typically refers to pie charts used for categorical data, and a diagram showing relationships might pertain to various other types of data visualizations, but does not specifically focus on distribution like a histogram does.