In the following chapter, we will introduce the important concept of power series. Power series play a very prominent role in the analysis. They are both: objects of interest and tools helping to study other objects of interest. In some way, they are generalizations of polynomials. Most results about power series are applicable for both, real-valued and complex-valued analysis. Therefore, you can read the following text as applying for both cases, unless there is a suggestion made that a distinction has to be made.
