Rocks are solid aggregates of minerals or mineraloids that form the Earth's crust. They are classified into three main types: igneous, sedimentary, and metamorphic. Each type has unique characteristics and formation processes, contributing to the diverse landscape we see around us. For example, igneous rocks form from cooled magma or lava, while sedimentary rocks are created from the accumulation of mineral and organic particles. Rocks play a crucial role in our environment and are essential for various human activities. They provide resources like minerals and fossil fuels, and are used in construction and art. Understanding rocks helps us learn about Earth's history and the processes that shape our planet.