High magnetic fields is a research concept and experimental methodology focusing on the study of matter and physical phenomena when subjected to magnetic fields of exceptionally high intensity, significantly exceeding those readily achievable with standard laboratory equipment or found in natural environments. This field investigates fundamental interactions, induces novel electronic and magnetic states, and reveals emergent properties of materials that are inaccessible under weaker field conditions, serving as a critical tool for advancing condensed matter physics, quantum materials research, and fundamental physics investigations.