This document provides information about the three main types of rocks: igneous, sedimentary, and metamorphic. It describes how each type forms and gives examples. Igneous rocks form from cooling magma or lava. Sedimentary rocks form from compaction and cementation of sediments. Metamorphic rocks form from heat and pressure altering existing rocks. The document also explains key processes that change rocks, such as weathering, erosion, melting and cooling. It introduces the concept of the rock cycle to show how rocks continuously change between the three types.