This book is focused on neural networks in an R environment. We have used R version 3.4.1 to build various applications and the open source and enterprise-ready professional software for R, RStudio version 1.0.153. We focus on how to utilize various R libraries in the best possible way to build real-world applications. In that spirit, we have tried to keep all the code as friendly and readable as possible. We feel that this will enable our readers to easily understand the code and readily use it in different scenarios.