The Tuffle Backend Server will track the state of the game. The backend is responsible for handling the logic that powers the game - from the selection of a random Tuffle secret word, to the verification of the validity of a submitted guess.
See the Tuffle Project Spec for detailed instructions on the Tuffle Backend Server implementation, the API that enables the Tuffle frontend and backend to communicate, and an overview of how the data sent from the server is parsed on the frontend to update the UI.