Additive Manufacturing (AM) is capable of creating delicate, complex and functionally advanced parts. AM is commonly recognized for creating parts for the aerospace, biomedical, and energy sectors. This chapter addresses the latest advancements in AM concerning the thermodynamics of processes and microstructures, and the processes of digital control. The analysis of laser and electron-beam processes especially focuses on the thermal–mechanical conversion, the anisotropic microstructure, and the phase-changing processes. The flexibility in the materials and efficiency in the use of materials are unmatched in crafting for defense manufacturing, space exploration, and power systems AM makes. The development of smart fabrication systems is the integration of high-level computing, multi-scale simulation, artificial intelligence, and autonomous systems. The use of artificial intelligence, advanced machine learning, and digital twins for real-time monitoring and prediction of defects is are breakthrough advancement for AM systems. With life-cycle energy modeling and powder reuse, AM processes comply with global environmental standards. The development of 4D printing, nanocomposite reinforced solders, and microwave-assisted fusion of layers introduces many new scientific challenges within additive manufacturing (AM). In this context, the combination of materials science, artificial intelligence, and green engineering transforms additive manufacturing into a new paradigm as a data-driven, self-optimizing, and self-sustaining system of manufacturing, which can both spatially and functionally design the geometry and materials of a product with unmatched precision.