What is configureStore and what advantages does it provide?

configureStore is Redux Toolkit's function for creating a store. It wraps the core createStore with good defaults, so one call replaces the manual store setup.

• Reducers combined. Pass an object of slice reducers, and it calls combineReducers for you.
• Middleware included. It adds the thunk middleware. In development it also adds checks that catch accidental state mutations and non-serializable values.
• DevTools connected. It sets up the Redux DevTools Extension automatically.

Options such as middleware and devTools change these defaults. Since createStore is now deprecated, configureStore is the standard way to create a store.

const store = configureStore({
  reducer: {
    counter: counterSlice.reducer,
    user: userSlice.reducer
  }
});