Which graph shows relationships through points representing data values?

The scatter plot is the correct choice as it effectively illustrates relationships between two variables using points to represent data values. Each point on the scatter plot corresponds to one data pair, with the position of the point indicating the values for each variable on the respective axes. This visual format allows for the identification of patterns, correlations, or trends in the data, such as clustering or linear relationships.

In contrast, a histogram displays data distribution by showing the frequency of values in specified intervals, while a pie chart illustrates parts of a whole through proportional segments, and a bar graph uses rectangular bars to compare quantities across different categories. These options do not represent data relationships in the same point-based fashion that a scatter plot does.