A fault zone is a region of the Earth's crust where rocks have fractured and moved along a fault line due to tectonic forces. These zones are characterized by a concentration of faults that can range in size from small fractures to large, active fault lines capable of producing earthquakes. Fault zones play a crucial role in the dynamics of plate tectonics and seismic activity, as they represent areas of high stress and strain accumulation. Scientists study fault zones to better understand earthquake activity, the movement of tectonic plates, and the formation of mountain ranges. This research area involves field observations, geophysical surveys, and modeling to analyze the mechanics and behavior of fault zones.