In the above code we are passing the user id and from the resource model 'sales/order_collection' we are loading the orders with the customer id as $customer_id in descending order to get the latest order on the top.
Now we need to load the list of all products from the orders for that purpose we are required to work on a foreach loop as :
In the above code we loaded the order from the model 'sales/order' with the order id as $_order->getId();
Afterwards we loaded the items of the order of type simple then in the other nested foreach loop we printed products and their prices one by one.
In this way we will get the products list from the orders of the logged in customer.