Bar charts display a series of discrete values and histograms display data values that are part of a continuous range.

As a consiqunce of this the value of a bar graph data point can be described only by the length of the bar. However the bar on a histogram can be described using its hieght and base width. In a histogram the area of the bar is also significant as it is proprtional to the desity approximation in that range.

The bars in a histogram effectively divide the area under the curuve into a series of slices (normally equal).

Unlike a bar chart t he bars on a histogram have no space between them as they represent a continuous range of values. Seperating the bars would create confusion as there should be no space betweeen neigbouring valuies on the number line.

It is common to seperate bars in a bar chart as each bar represent an individual item who value is represented only by the size of the bar. Because the bars on a bar chart are seperate they can be freely arranged in many different ways to display information. It is common to use a bar's label to arrange the bars in alphabetical order or part of an acenting or decending series of dates.

It is this flexibility that makes bar charts susceptablke to distortion of information as trends can be manufactured or exagerated easily by reordering data values.