Petrology is the branch of geology that studies rocks, their origins, composition, and structure. It helps scientists understand how different types of rocks form and change over time. Petrologists analyze minerals within rocks to determine their history and the processes that created them, such as volcanic activity or metamorphism. There are three main types of rocks studied in petrology: igneous, sedimentary, and metamorphic. Each type has unique characteristics and formation processes. By examining these rocks, petrologists can gain insights into Earth's history, including past environments and geological events.