Following Order Status Workflow will help you understand how the the ordering process is when one is placed by a customer. Otherwise, the order status workflow will show store admins that each order status is corresponding to a state.
For example, the first stage of a new order that is not paid and delivered, Magento 2 system will auto-set it to “Pending”. Once you complete an invoice or you update the shipment, the status is changed to “Processing”, and when you both generate an invoice and you ship the order the status is changed to “Complete”.
Let have a detailed view of the order status workflow with the chart below.
Ref: Magento 2 User Guide
It comes to the end of tutorial: Order Status Workflow in Magento 2.