In the post-Moore era, the increasingly prominent bottleneck of power consumption in conventional devices, together with the rapidly growing demand for computing power from artificial intelligence, poses unprecedented challenges to the performance of memory and logic chips. Consequently, the development of novel memory and logic devices has become a research hotspot to address these issues. Orbitronics, which focuses on the generation, transport, and manipulation of electronic orbital angular momentum, opens a new pathway to overcome the technical bottlenecks of conventional spintronic devices and realize high-performance magnetic memory and logic devices. This review summarizes the research progress on the orbital Hall effect and related devices in terms of physical mechanisms, torque efficiency manipulation, and device applications. First, the microscopic mechanisms of the orbital Hall effect and orbital Rashba-Edelstein effect in materials with weak spin-orbit coupling are introduced, and the physical mechanisms for achieving efficient charge-to-orbital current conversion are discussed. Then, the generation mechanisms of orbital torque are elucidated, followed by a systematic overview of characterization methods and modulation strategies for orbital torque efficiency. On this basis, the research progress on orbital torque-driven magnetization switching of perpendicularly magnetized ferromagnetic materials is reviewed. Further focusing on device applications, the performance breakthroughs achieved by orbital torque-driven magnetic tunnel junctions in terms of write power consumption and switching speed are discussed. Finally, key advances in the field of orbitronics are summarized, and an analysis and outlook on current challenges and open issues are provided.