Micromagnetics is a research field focused on understanding and modeling the behavior of magnetization in magnetic materials at mesoscopic length scales, typically ranging from nanometers to micrometers. It employs continuum theoretical and computational methods, primarily based on the Landau-Lifshitz-Gilbert equation, to simulate static and dynamic magnetic phenomena such as the formation and evolution of magnetic domain structures, domain wall motion, magnetization switching, and the effects of thermal fluctuations. This approach is essential for the design and analysis of magnetic recording media, spintronic devices, magnetic sensors, and other applications leveraging nanoscale magnetism.