A Pie chart is a representation of categories all put in a circle in the form of a pie or a pizza. The difference is just that all slices are not proportional as we get in a pizza. Here the size of a slice varies according to the numeric variable present in the dataset associated with that category.
Why do you need it?
We need a pie chart to visualize different categories of data in such a way that it will look appealing. Collectively giving us a brief overview of which category is profitable and which one is representing a loss. The category that represents loss is the one that needs work.
What kind of data you can visualize with it?
The pie chart is best suited to categorical-data. Assume you have a dataset that is categorized as “Breed of birds” in a pet store and count of available birds per category, then this chart is the best alternative. It will show which breed is stocking out and which one is in excess. This shows that the one stocking out could be the best seller.