Grouping data into similar categories is an essential operation in any data analysis task. In this chapter, we discussed different grouping techniques, including groupby mechanics, rearranging, reshaping data structures, data aggregation methods, and cross-tabulation methods. In addition to this, we also checked various examples for each case. 

In the next chapter, we are going to learn about correlation, which describes how two or more variables can be related. In addition to this, we will look at different types of correlation techniques and their applications with suitable examples.