The document describes the rock cycle, which is the process by which rocks are formed at the Earth's surface and within the Earth over geological time. It involves several steps: weathering and erosion of existing rocks, transportation and deposition of sediment, burial and compaction of sediment into sedimentary rock, deformation and metamorphism of existing rocks due to heat and pressure, melting of rocks to form magma, crystallization of magma to form igneous rock, and uplift and exposure of rocks at the surface through tectonic activity. The major rock groups - sedimentary, metamorphic, and igneous rocks - are formed through this continuous process.