Nowadays, additive manufacturing (AM) has been increasingly developed and applied in many fields. As a rapid development of AM, similar terms are appeared, such as 3D printing, freeform fabrication, rapid tooling, rapid manufacturing, direct digital manufacturing, layer manufacturing, additive process, 4D printing, 3D bioprinting, and 3D biofabrication. This paper reports and analyses the development of these terms. Moreover, it tries to give the readers a comprehensive understanding of these terms and their development.