[caption id="attachment_533" align="alignnone" width="200"] Histogram[/caption]
A histogram is the graphical representation of numerical data. It is a very common type of graph and consists of an x and a y axis. The representation of numerical data on a graph paper is a better way of conveying the import of the data. The term was coined by Karl Pearson and histograms usually use bar graphs in their representations. A histogram has both advantages and disadvantages and they must be constructed with care and accuracy.
Histograms generally represent how frequently an event occurs and the time in which they occur. This is the primary kind of data that histograms deal with, and therein lies its importance. For example, a histogram may convey how frequently injuries occur among a certain group of people, and the times at which they occur.
The time is labeled on the x axis and the frequency on the y. This makes it easier to represent numerical data visually. By doing so, histograms make a greater impact than the plain numerical presentation of the same data.
Histograms are fairly simple to understand. However, they do provide valuable inputs about the data and the changes observed. A histogram can be constructed with relative ease making it one of the most popular graphs.