A cart is an in progress Order that has not yet been completed, and can be created through Staff View or Community Hub. Carts save themselves as you proceed through the order process, and are converted to an Order once they have been submitted, with or without a payment.
If you make a payment in Staff View on a cart and save a credit card payment, but do not submit the cart, the payment will still be sent to your Payment Gateway as the save button during this portion of the order process is directly linked to the gateway to authorize the cart in question. This will show as a Cart Payment and Cart Payment Line in the respective related lists on the cart.
Cart Items and Cart Item Lines
A cart item is an individual product that has been added to a cart, which will be converted into an order item once a cart has transitioned into an order. In addition, each cart item will have at least one cart item line. For example, if a constituent were to purchase multiples of the same product, they would have one cart item with a quantity matching the purchase number, and an individual cart item line for each of the products.
Cart Payments and Cart Payment Lines
Cart payments are just that - a payment made on a cart through any payment method, before a cart has been converted into an order, which is separated into cart payment lines to show how much of the payment was attached to each cart item line - cart payment lines are converted into payment lines when a cart is submitted.