Geological structures refer to the various physical features and arrangements of rocks and sediments within the Earth's crust. These structures include folds, faults, and joints, which are formed through processes like tectonic activity, erosion, and sedimentation. Understanding these formations helps geologists interpret the Earth's history and the forces that shaped it. Common examples of geological structures are mountain ranges, which often result from the collision of tectonic plates, and fault lines, where rocks have broken and moved. Studying these structures is essential for fields like geology, seismology, and natural resource management.