Magento_Checkout module
Magento\Checkout module allows merchant to register sale transaction with the customer. Module implements consumer flow that includes such actions like adding products to cart, providing shipping and billing information and confirming the purchase.
Observer
This module observes the following events etc/events.xml sales_quote_save_after event in Magento\Checkout\Observer\SalesQuoteSaveAfterObserver file. /etc/frontend/events.xml customer_login event in Magento\Checkout\Observer\LoadCustomerQuoteObserver file. customer_logout event in Magento\Checkout\Observer\UnsetAllObserver
Layouts
The module interacts with the following layout handles in the view/frontend/layout catalog_category_view catalog_product_view checkout_cart_configure checkout_cart_configure_type_simple checkout_cart_index checkout_cart_item_renderers checkout_cart_sidebar_item_price_renderers checkout_cart_sidebar_item_renderers checkout_cart_sidebar_total_renderers checkout_index_index checkout_item_price_renderers checkout_onepage_failure checkout_onepage_review_item_renderers checkout_onepage_success default
data-slots=text