A seismograph is a scientific instrument used to detect and record the vibrations caused by earthquakes. It consists of a mass suspended on a spring, which remains still while the ground shakes. When an earthquake occurs, the ground moves, causing the mass to sway. This movement is captured on a rotating drum or digital recorder, creating a visual representation of the seismic waves. Seismographs are essential for understanding the Earth's tectonic plates and predicting potential earthquakes. Scientists analyze the data collected by seismographs to determine the earthquake's magnitude and location, helping communities prepare for future seismic events and improve safety measures.