1) Genre is important for both film producers and audiences. Producers use genre to engage target audiences and be successful, while audiences need to be interested in a genre to watch and enjoy a film.
2) Genre theory is used to categorize films based on factors like storyline, director, and audience expectations. It provides a shortcut for describing films.
3) Genres can change over time as different social groups and audiences emerge with different interests. For example, westerns were once very popular but new genres like sci-fi and thrillers developed.