Histogram is a kind of bar graph and has a similar appearance as a column graph but without any gaps between the columns.These graphs are used to depict data from the measurement of a continuous variable. Categories are of continuous measurements such as temperature, time, inches etc.
Usually, a histogram has equal width bars, but when the class intervals are different in size then this would not be the case.
Choosing the correct width of the bars is one of the important things while drawing a histogram.
Histograms give a good visual impact and can be used to compare to a normal curve.
One of the limiting factors of a histogram is that, because the data is grouped into categories, one cannot read the exact values.
Secondly, it is difficult to compare two data sets and can be used only where continuous data is available.