How does the agent update the ocs server?

Hi, I'm using ocs agent version 2.1.1. How does the agent update? Do I need to put it on CRON or run like a daemon? How often does it update? How does it update the software on the ocs server? Does it overwrite the data already contained in the OCS server? UPDATE [mysql] or INSERT a new? Do you have any validation to know if the data is already registered?

ahh...
What is Add file to "manage your ocs-ng clients"?