A class is a set of instructions that dictate how a specific instance of an object is to be created. A class is, in a sense, a recipe.
In the case of this book, a class includes details of authoring, editorial processes, and publication steps. These steps are, hopefully, invisible to anyone reading this book; they are part of the internal implementation of the class. Following these steps will produce an instance of the PowerShellBook object.
It is often necessary to look up the instructions for using a class in the .NET class library on MSDN:
https://msdn.microsoft.com/en-us/library/mt472912(v=vs.110).aspx
The starting point for creating an instance of an object is often what is known as a Constructor.
