A magma chamber is a large underground pool of molten rock, known as magma, located beneath the Earth's surface. This chamber forms when magma rises from the mantle and collects in a reservoir, often situated within the crust. The pressure and temperature in the chamber can lead to the formation of crystals and gases, influencing the composition of the magma. When the pressure in the magma chamber becomes too great, it can cause volcanic eruptions. During an eruption, the magma is expelled through a vent, which can create features like volcanoes and lava flows. Understanding magma chambers is essential for predicting volcanic activity and assessing potential hazards.