DraftOrder API vs Order API for prepaid orders

[KBell]

Which API should be used to create a pre-paid order within Shopify? DraftOrder, Order, other?

We're building an app to allow our Shopify merchants to view and fulfill orders placed on our e-commerce platform. 

Paid orders sent from our platform will be sent to Shopify for merchants to take fulfillment action: ship or cancel.

We have product sync integration just about completed: Shopify product catalog send to our e-commerce platform where they are creating or updated.

Planning out the next phase, order integration.

Thanks in advance.