In this chapter, we have examined NumPy arrays to get an understanding of their capabilities to manipulate data and performe operations on data including selecting elements, vectorization, Boolean selection, reshaping, stacking, concatenation, splitting, and slicing. NumPy has many other features, but these are the ones that are important to understand as they will set a frame of reference for understanding the operation of pandas Series and DataFrame objects. All the concepts covered in this chapter will be examined in much more detail in the next two chapters, where they are applied to pandas objects, which extend these capabilities to provide a much richer and more expressive means of representing and manipulating data than is offered with NumPy arrays.