In the context of an application, "checkout" typically refers to the process of completing a transaction or finalizing a purchase. It's the step where a user confirms their order and provides payment details before the purchase is processed. Here's a breakdown of what "checkout" means in different scenarios:

1. E-commerce: In online shopping, "checkout" is the stage where you review your shopping cart, enter shipping information, and make the payment².
2. In-app Payments: For mobile applications, "checkout" can mean the secure process where users enter their payment details directly within the app to complete a purchase³.
3. Physical Stores: At physical retail stores, "checkout" refers to the area where customers pay for their items before leaving.
Libraries or Rentals: "Checkout" can also mean the process of borrowing an item, like a library book, where you take the item for use outside of the premises after it's been logged or scanned.