What is caldera definition?

A caldera is a large, bowl-shaped depression formed when a magma chamber beneath the Earth's surface is emptied during a volcanic eruption. After the chamber is emptied, the weight of the overlying rock causes the ground to collapse, creating a giant crater. Calderas can range in size from a few kilometers to tens of kilometers in diameter. They can be found at the summit of shield volcanoes, composite volcanoes, and stratovolcanoes. Some calderas are filled with water and become lakes, while others are filled with lava and become lava fields. Calderas are often associated with high-risk volcanic hazards, such as pyroclastic flows, lahars, and explosive eruptions.