Users can select "Add to Cart" from an Order Template to simply add the template items to their shopping cart.  Quick Checkout takes that concept a step further.

With Quick Checkout, the user can set a default Ship To and Shipping Method on an Order Template.  Then, instead of adding the items to the cart, they can click the "Quick Checkout" button to place the order directly from the Order Template.

Quick Checkout is a valuable feature for some situations but may not be a good fit for more complicated orders.  For instance, Credit Card payment is not available in Quick Checkout.  Certain shipping options that require further input like Will Call/Customer Pickup and Collect Shipping are not available in Quick Checkout.  

See the details on how to enable this feature on an Order Template in the How do I Enable Quick Checkout for an Order Template article.