A geological fault is a fracture or zone of weakness in the Earth's crust where rocks on either side have moved relative to each other. This movement can occur due to tectonic forces, leading to earthquakes and other geological activity. Faults can vary in size, from a few centimeters to hundreds of kilometers long, and are classified into different types, such as normal faults, reverse faults, and strike-slip faults. Faults are often found along the boundaries of tectonic plates, which are large sections of the Earth's crust that float on the semi-fluid mantle beneath. The interaction between these plates can create stress that eventually leads to a sudden release of energy, resulting in an earthquake. Understanding geological faults is crucial for assessing earthquake risks and planning safe construction practices in affected areas.