Difference between due date and completed by dates in learning assignment page by learn admin

Summary:

Content (please ensure you mask any confidential information):

When a learning administrator creates a required learning assignments there is a due date field and complete by field .

What is significance of complete by field?

Is completed by field visible to learner self service?

Can both due date and complete by values be different?

Version (include the version you are using, if applicable):

25A

Code Snippet (add any code snippets that support your topic, if applicable):