Additive Manufacturing (AM) Technologies is has become widely popular manufacturing technique in the last 30 years. Additive manufacturing uses 3D Computer Aided Design (CAD) model to manufacture parts layer by layer through adding materials. Additive Manufacturing allows to manufacture complex geometries that cannot be manufactured using conventional manufacturing techniques. Additive manufacturing permits customized designs and prototypes to be produced easily. Over the past three decades thorough research has been done to commercialize AM techniques in varied areas. As a result of these research, AM techniques are being used in automotive, aerospace, biomedical, medicine, energy and in many other areas. Due to its advantage over the traditional manufacturing techniques, additive manufacturing is seen as one of the enablers that started fourth industrial revolution. In this chapter, we will review additive manufacturing processes by introducing its history, presenting different technologies of AM, giving examples of AM usage in different application areas and its impact on our society.