From: https://data36.com/pandas-tutorial-1-basics-reading-data-files-dataframes-data-selection/

https://www.geeksforgeeks.org/python-union-two-lists/  

1. two types of data structures in pandas: Series and DataFrames

   (1)  Series: a pandas Series is a one dimensional data structure (“a one dimensional ndarray”) that can store values — and for every value it holds a unique index, too.

Pandas Series example

    (2) DataFrame: a pandas DataFrame is a two (or more) dimensional data structure – basically a table with rows and columns. The columns have names and the rows have indexes.

Pandas DataFrame example