What is the difference between the "Combined keywords" and "Combined imported keywords" reports?


Under the keywords widget in my dashboards, these reports are displayed as related reports. (See screenshot) I am not quite sure what these reports are about. Matomo calls them “Combined keywords” and “Combined imported keywords” reports.

Does anyone know what the difference is between these reports?
Specifically, what data Matomo is accessing for these reports.

Thank you in advance!