This document discusses the four main types of rocks: igneous, sedimentary, metamorphic, and defines what rocks are. It provides definitions for each rock type - igneous rocks form from cooled lava or magma, sedimentary rocks form from compressed sediments, and metamorphic rocks change due to temperature and pressure alterations. It also includes links to audio samples of different rocks and a video on the rock cycle. In the end it acknowledges the sources that helped create the presentation.