The most common type of rock on Earth is igneous rock. This category of rock forms from the cooling and solidification of molten rock material, either magma beneath the Earth's surface or lava that has erupted onto the surface. Common examples of igneous rock include granite, which is formed from slow cooling beneath the surface, and basalt, which erupts as lava flows. Due to volcanic activity and the constant recycling of the Earth’s crust, igneous rocks are prevalent and play a crucial role in the planet's geology, forming the foundation of many landscapes.