First, the term "neural networks" may create a snapshot of a brain in our minds, particularly for those who have just been introduced to it. In fact, that's right, we consider the brain to be a big and natural neural network. However, what if we talk about artificial neural networks (ANNs)? Well, here comes an opposite word to natural, and the first thing now that comes into our head is an image of an artificial brain or a robot, given the term "artificial." In this case, we also deal with creating a structure similar to and inspired by the human brain; therefore, this can be called artificial intelligence. So, the reader who doesn't have any previous experience with ANN now may be thinking that this book teaches how to build intelligent systems, including an artificial brain, capable of emulating the human mind using Java codes, isn't it? Of course, we will not cover the creation of artificial thinking machines such as those from the Matrix trilogy movies; however, this book will discuss several incredible capabilities that these structures can do. We will provide the reader with Java codes for defining and creating basic neural network structures, taking advantage of the entire Java programming language framework.