Genre is an important media concept that helps industries market and sell products by categorizing different media texts. It allows audiences to easily find the type of media they enjoy, such as rock music fans browsing all rock CDs together. The music industry categorizes genres like rock, pop, indie, and dance which have distinguishing characteristics and styles. Sub-genres further classify genres to target more specific tastes, for example metal and surf rock are sub-genres of the rock genre that have opposing styles.