Activities and Checkin/Merge

Hi,

suppose I have a repository landscape with a workspace under
baseline-control. The workspace contains my VCR's. Checkout is done with
DAV:apply-to-version and DAV:activity-set (href or new). So Work in process
is represented by working-resources collected in activities.


What is the difference of performing a checkin on the activity or do a merge
of that activity to the workspace the VCR's are located in with
DAV:checkin-activity?

Regards,
Daniel