Earthquakes primarily occur due to the movement of tectonic plates. The Earth's lithosphere is divided into several large and small plates that float on the semi-fluid asthenosphere beneath them. When these plates interact at their boundaries—such as through subduction, collision, or sliding past each other—stress builds up over time. When the stress exceeds the strength of rocks, it results in a sudden release of energy, causing an earthquake. Monitoring seismic activity helps in understanding these natural phenomena and aiding in earthquake preparedness and risk mitigation.