Igneous rocks are formed from the solidification of molten material called magma or lava. They are classified into two main types: Volcanic rocks, which cool quickly on the Earth's surface, and Plutonic rocks, which cool slowly beneath the surface. Common examples include Basalt and Granite. These rocks play a crucial role in the Earth's geology, providing insights into volcanic activity and the planet's formation. Igneous rocks are often characterized by their crystalline texture and can vary widely in color and composition, making them essential for understanding geological processes.