A quote is a temporary object that represents the customer’s shopping cart before it is converted

into an order1. A quote can be created by a guest or a registered customer, and it can be active or

inactive depending on whether the customer has completed the checkout process or not2.

The quote table stores the basic information about the quote, such as the customer ID, email,

currency, subtotal, grand total, shipping method, payment method, and so on2. Each row in the

quote table corresponds to one quote object, identified by a unique entity ID2.

The quote item table stores the details of each product added to the quote, such as the product ID,

SKU, name, price, quantity, discount amount, tax amount, and so on2. Each row in the quote item

table corresponds to one quote item object, identified by a unique item ID2. A quote item object is

associated with a quote object by the quote ID column in the quote item table2.

When a customer adds a product to the cart, Magento creates or updates a quote object and a quote

item object for that product. The quote object is initialized by the Magento\Quote\Model\Quote

class, which implements the Magento\Quote\Api\Data\CartInterface interface3. The quote item

object is initialized by the Magento\Quote\Model\Quote\Item class, which implements the

Magento\Quote\Api\Data\CartItemInterface interface3.

Magento uses various classes and interfaces to manipulate the quote and quote item objects, such

as

the

Magento\Quote\Model\QuoteRepository

class,

which

implements

the

Magento\Quote\Api\CartRepositoryInterface interface for saving and retrieving quotes from the

database3, and the Magento\Quote\Model\QuoteManagement class, which implements the

Magento\Quote\Api\CartManagementInterface interface for creating and submitting quotes to

orders3.

Magento also uses various events and observers to perform additional actions on the quote and

quote item objects, such as applying discounts, calculating taxes, validating stock availability, and so

on.

Some

of

these

events

are:

sales_quote_add_item,

sales_quote_collect_totals_before,

sales_quote_collect_totals_after,

sales_quote_save_before,

sales_quote_save_after,

sales_model_service_quote_submit_before, sales_model_service_quote_submit_after.

Magento provides various APIs for interacting with the quote and quote item objects, such as the

Magento\Quote\Api\CartManagementInterface API for creating empty carts and placing orders from

carts, the Magento\Quote\Api\CartItemRepositoryInterface API for adding, updating, and removing

items from carts, and the Magento\Quote\Api\CouponManagementInterface API for managing

coupons for carts.