Is there a difference between a 403 and a 401 error in the context of Flutter authentication?

Yes, there's a crucial distinction. A 401 Unauthorized error indicates that the request lacks authentication – the user hasn't provided credentials or the credentials are invalid. A 403 Forbidden error, on the other hand, means the user *is* authenticated, but doesn't have permission to access the requested resource. Understanding this difference is vital for proper error handling and user experience.