The document discusses the rock cycle and how rocks are formed and transformed. It describes the three main rock types - igneous, sedimentary, and metamorphic - and the processes involved in their formation. Igneous rocks form from the cooling of magma, either deep underground or at the surface. Sedimentary rocks form from the compaction and cementation of sediments. Metamorphic rocks form from changes to existing rocks via heat, pressure, and chemical reactions in the Earth. The rock cycle diagram shows how rocks continuously transform between these three types through geological processes over long periods of time.