If you want to secure your workstation without closing the Visualizer, you can lock it. Locking the Visualizer retains your user name, but requires your password to get back in. You might choose to lock the Visualizer, rather than log out or close the Visualizer completely, if you are taking a break or walking away from your workstation for a few minutes. If you are leaving for the day, you probably want to close and exit the Visualizer.