What are the swallows in swallows and Amazons by Arthur Ransome?

In "Swallows and Amazons" by Arthur Ransome, the "Swallows" are a group of four children—John, Susan, Tatty, and Roger Walker—who embark on sailing adventures in the Lake District of England during their summer holiday. They explore the local lakes and engage in imaginative play, particularly in their boat named the "Swallow." The narrative highlights themes of adventure, friendship, and the joys of childhood, as the Swallows interact with another group of children, the "Amazons," who are engaged in their own adventures.