What is a sub theme?

A sub-theme is a secondary or supporting idea that complements the main theme of a work, such as a book, film, or artwork. It provides depth and nuance, allowing for further exploration of the primary topic. Sub-themes often address specific aspects or perspectives related to the main theme, enriching the overall narrative and engaging the audience on multiple levels. They can reveal character motivations, societal issues, or emotional undertones that enhance the central message.