1. Adding Products to Cart

1. Product Selection:
   • React: Users browse products displayed using React components.
2. Add to Cart Action:
   • React: A button triggers the addition of a product to the cart. The product ID and quantity are passed to the cart state.
3. State Management:
   • Redux: Manages the cart state, updating it with the new product details.
4. Persisting Cart Data:
   • LocalStorage: Stores the cart data locally to maintain the state across page reloads and sessions.
   • Backend Sync (Express.js/MongoDB): Optionally, syncs cart data to the server for logged-in users to ensure data consistency.

2. Viewing the Cart

1. Cart Display:
   • React: Fetches cart data from state (Redux) or LocalStorage and renders it in a user-friendly format, showing products, quantities, and total price.
2. Dynamic Updates:
   • React: Updates the cart display dynamically as users add or remove products.
3. Cart Calculations:
   • React/Redux: Computes total cost and updates the cart summary, providing real-time feedback on changes.

3. Modifying Cart Items

1. Update Quantity:
   • React: Provides input fields or buttons to increase/decrease product quantities in the cart.
2. Remove Items:
   • React: Includes a button to remove items from the cart.
3. State Update:
   • Redux: Updates the cart state with new quantities or removed items, ensuring the UI reflects these changes immediately.
4. Persist Changes:
   • LocalStorage/Backend: Updates stored cart data to reflect changes.

4. Proceeding to Checkout

1. Checkout Button:
   • React: Provides a button that directs users to the checkout process.
2. Validation:
   • React: Ensures users have valid items in the cart before proceeding.
3. Redirect to Checkout:
   • React Router: Navigates to the checkout page, where further actions are taken to complete the purchase.

5. Checkout Process