Histogram vs Bar Graph I have data for number of patients used to collect the data in a hospital for each day. I want to display them as a graphical representation of number of patients used to collect the data for each week. Which graph is more suitable for this? Histogram or Bar Graph? Please explain the pros and cons of each of them. Also if you find any graph better than them, please tell me and also justify it.
 A: This answer depends on what you want to show. To explain I will think that you need to present the number of patients.
If you want to present how the number of patients or other summary changes weekly, the bar graph is better.
On the other hand, if you want to present how many weeks has some number of patients, the histogram is better.
In truth, a bar graph and histogram are almost the same. The difference between them is that on histogram you will specify the width of each category and on the bar graph you will present the bins with any aggregation.
A: You should use bar chart. Histograms are used for continuous variables.  You want to show the number of patients per week. Week is a discrete variable, hence you would use a bar chart. Your x variable would be the week number: week1, week2, and so on. Your y variable will be the number of patients for that week.
Which graph is better depends on what you want to convey in your visualization, assuming the graph is suitable for the type of the variable.  For example, let's say you want to convey the number of patients last 3 weeks. In this case, you can use a line chart or a bar chart.  If you want to convey a trend, then perhaps a line chart would be better.
For more info on histogram: https://en.wikipedia.org/wiki/Histogram
