Definition of Google Checkout:
Google-owned payment processing service designed to make paying for items online easier for buyers. It allows users to store credit and debit card information, and shipping address in a Google Account, which eliminates the need to re-enter it each time the user goes shopping online. Additional benefits for buyers using Google Checkout is the ability to check status on all orders from multiple websites in a single page offered through your Google Checkout account.
Meaning of Google Checkout & Google Checkout Definition