Over the years, there has been an increased demand for the manufacture of objects and products of high complexity, leading to the evolution of manufacturing processes. As a result, several technologies have been developed to try to support these market needs. Among these technologies, we can highlight the 3D printers, which in recent years has been shown a popularization in the global media. Another phenom which has been seen along the last couple years is the rise of industry 4.0. Into the main foundations of this new industry revolution, we can highlight the 3D printers, 3D scanners, artificial intelligence and virtual/augmented reality. For this reason, the main goal of this book is to introduce basic concepts about all the main 3D printing technologies, presenting how 3D printers help industry 4.0 to rise.