The "Four Branches" refers to a collection of four interconnected tales from Welsh mythology, primarily found in the Mabinogi. These stories are centered around the adventures of various characters, including Pwyll, Bran, and Manawydan, and explore themes of magic, transformation, and the relationships between humans and the supernatural. Each branch is distinct yet linked, showcasing the rich narrative tradition of Celtic folklore. The tales highlight the importance of honor, loyalty, and the consequences of choices, making them significant in understanding Welsh culture and its mythological heritage.