Underground film refers to a genre of cinema that operates outside the mainstream film industry. These films often challenge conventional storytelling, explore experimental techniques, and address taboo subjects. They are typically produced with low budgets and may be distributed through independent channels, film festivals, or underground screenings. This type of filmmaking is associated with various movements, such as the avant-garde and counterculture movements of the 1960s. Notable figures in underground film include Andy Warhol and John Waters, who pushed boundaries and created works that provoke thought and discussion.