why does the earth tremble sometimes?

The trembling of earth has occurred many unbelievable and disastrous events. Sometimes, the tectonic plates inside earth's crust moves and collide with each other. Sometimes, they slips over each other. This made the earth tremble. This gives so shocking waves and causes damage to land. Some natural factors occurred due to shaking of Earth are Volcanic eruptions, tsunami, earthquake, cyclones, landslides, and many more. The waves produced when tectonic plates moves and collide to each other are referred to as seismic wave.