Additive manufacturing is defined as the process of building components layer by layer from 3D digital models, typically using powder or wire feedstock melted by a high-energy heat source. The chapter begins with a concise overview of the various additive manufacturing methods currently in use. It then focuses on the solidification conditions typical of these processes, the resulting microstructures, and potential defects. Attention is also given to the post-processing of additively manufactured parts, including the generation and mitigation of residual stresses. The chapter concludes with a discussion on surface roughness and the influence of surface finishing treatments on the final properties of printed parts.