Both Redux Thunk and Redux Saga are middleware libraries for Redux that provide an approach for managing asynchronous logic in Redux applications.

Redux Thunk is a simple middleware library that allows you to write action creators that return a function instead of an action object. This function can then perform asynchronous operations, such as API calls, and dispatch actions once the operation is complete. The function can also dispatch additional actions based on the result of the operation. This approach is simple to learn and can be used for most common use cases. Redux Thunk is easy to set up and can be used with minimal configuration.

Redux Saga on the other hand, is a more powerful and flexible middleware library for managing asynchronous operations in Redux. It allows you to define complex, asynchronous logic as a sequence of steps, called sagas. Sagas can be used to handle more complex scenarios, such as race conditions, retries, and cancellation. Redux Saga uses generator functions to define sagas, which allows for more complex logic to be expressed in a more readable and intuitive way. However, it can be more difficult to learn and use effectively compared to Redux Thunk.