In a bar graph, which property is the same for all bars while their heights differ to show different frequencies?

A bar graph uses bars of **equal width** but **different heights**. The $y$-axis (vertical) shows the frequency on a numeric scale; the $x$-axis (horizontal) lists the categories. Reading: line up the top of each bar with the $y$-axis to find its frequency. Comparing: the tallest bar is the most common; the shortest is the least common. Bars are usually evenly spaced for clarity.