Difference Between Bar Graph And Histogram

What is a Bar Graph?

A bar graph also referred to as Bar Chart or Bar Diagram is a pictorial representation of data that uses bars to compare different categories of data. It displays grouped data by way of parallel rectangular bars of equal length but varying width. The bars can be plotted vertically or horizontally. A vertical bar chart is sometimes referred to as a Column Chart.

A bar graph shows comparisons among discrete categories. One axis of the chart shows the specific categories being compared and the other axis represents a measured value. Some bar graphs present bars clustered in groups of more than one, showing the values of more than one measured variable.

Bar graphs are an extremely effective visual to use in presentations and reports. They are popular because they allow the reader to recognize patterns or trends far more easily than looking at a table of numerical data.

Parts Of A Bar Graph

• The title (offers a short explanation of the contents of the graph).
• The source (explains where the information in the graph was found).
• X-axis (the X-axis has numbers representing different time periods or names of things being compared.
• Y-axis ( the Y-axis has numbers representing the quantity of variable being measured).
• The Data (information contained in the bar graph).
• The Legend (shows what each bar represents).

What You Need To Know About Bar Graph

1. A bar graph is a pictorial representation of data that uses bars to compare different categories of data. It displays grouped data by way of parallel rectangular bars of equal length but varying width.
2. A bar graph is often used to show a visual comparison of discrete variables. A discrete variable is a variable that is countable in a finite amount of time. For example you can count the number of students in a school or you can count the number of breads in a shop.
3. Bar charts are used to display relative sizes of the counts of variables.
4. Bar graph is drawn in such a way that there is proper spacing between bars in a bar graph that indicates discontinuity (because it is not continuous).
5. Items of the bar graph are considered as individual entities.
6. In a bar graph, variables are ordered alphabetically or in terms of sizes from highest to the lowest. In other words, blocks are rearranged from the highest to the lowest.
7. The columns are positioned over a label that represents a categorical variable.
8. The width of the bars in a bar graph is always same.

What is a Histogram?

Histogram was first introduced by Karl Pearson; Histogram refers to a type of bar chart that is used to represent statistical information by way of bars, to show the frequency of continuous data. In other words, it provides a visual interpretation of numerical data points that fall within a specified range of values referred to as class or bins. 

Other than displaying a large amount of data and frequency of the data values, histogram can be used to determine the median and distribution of the data. Distributions of a histogram can be:

• Normal distribution
• A bimodal distribution
• A right-skewed distribution
• A left-skewed distribution
• Random distribution

Parts Of A Histogram

• The Title which explains the information contained in the histogram.
• X-axis, which displays scale of values which measurements fall under.
• Y-axis, which shows the number of times that the value occurred within the intervals, set by the x-axis.
• The Bars, in which the height of the bars shows the number of times that the values occurred within the interval while the width of the bar shows the interval that is covered.  For a histogram with equal bins, the width should be same across all bars.

What You Need To Know About Histogram

1. Histogram refers to a type of bar chart that is used to represent statistical information by way of bars, to show the frequency of continuous data. It indicates the number of observations which lie in-between the range of values referred to as class or bin.
2. A histogram is often used to show the frequency of continuous or non-discrete variable. A non-discrete variable is a variable that takes forever to count.  
3. Histograms are used to display the shape of distribution of the data.
4. The histogram is drawn in such a way that there is no gap between the bars.
5. Items of the histogram are numbers, which are categorized together, to represent ranges of data.
6. In histogram, rearrangement of the blocks from the highest to the lowest is not possible; variables are shown in the sequence of classes.
7. The columns are positioned over a label that represents a quantitative variable.
8. The width of rectangular blocks in a histogram may or may not be same.

Also Read: Difference Between Parameter And Statistics

Difference Between Bar Graph And Histogram In Tabular Form