A pie chart is a circular chart that is divided into wedges to illustrate the proportion of different categories as a whole.
Each wedge represents a category and the size of the wedge is proportional to the quantity it represents.
A bar chart, also known as a bar graph, is a chart that uses rectangular bars to represent different categories and the quantity they represent. The length of the bar is proportional to the quantity it represents.
In summary, pie charts are used to show the proportion of different categories as a whole, while bar charts are used to show the number of different categories. Both are types of statistical graphics used to represent data in a visual format.