3DM runs as a service under Windows, and as a daemon under Linux and FreeBSD. Normally after installation, the 3DM process starts automatically when you start your system.
It is a good idea to leave the 3DM process running on the system that contains your 3ware RAID controller. That way email alerts can be sent by 3DM, and administrators can manage the controller remotely, if remote administration is enabled.
When 3DM is running in the background on your computer, you can access the 3DM web application through your browser to check status information and manage your 3ware RAID controller.