Chapter 1 is a fairly easy read that introduces what Python scripting is and some things that be done with the scripting language. There is some programming terminology but you are given most of the definitions for these terms right away. Python is the programming language used by ArcGIS Pro and there are several reasons for this: it is a simple language and relatively easy to learn, it is free and open-source, and it is cross-platform. Being open-source means that the software can be freely shared as well as scripts written by other people making the Python community strong. Being cross-platform means that Python will work on different platforms such as Windows or macOS.
Python programming is commonly known as a scripting language rather than a programming language. Programming involves building components from scratch and is overall more complicated. Scripting takes already made components and manipulates or relates them to other components often producing an output. An example to book using is changing a line shapefile and generating equally spaced points along the line. You can also use Python scripting to automate tasks. An example given in the book is automating copying and pasting a certain type of shapefiles from a geodatabase with other types of shapefiles. This reduces human error and can be more efficient if there are hundreds of shapefiles. Plus, the script can be saved and used again later, saving more time.