Note: Before you get to know what default workflow stage means, you should know the basics of workflows, its stages and tasks.
When you create a new entry and save it, the entry is, by default, assigned the first stage of your workflow.
Initially, no user(s) and/or role(s) are assigned to the first stage of the Workflow as seen in the Assigned To section. You can assign user(s) and/or role(s) as per your need.
Also, the due date is not set for this workflow stage. So, you can assign a due date to the workflow stage as per your requirement.
To update this stage, refer our Change Entry Workflow Stage section.