What is 'Total Credit' in Order Total list? And how it is calculated?

Summary:

We see there is a field named 'Total Credit' under order total list. What is it? How is it calculated?

Content (required):

Please help me to undardarnd this field designation.

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

23A

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

NA