Ok look.
When your admin, you can push F8 to bring up the "yellow ball" and move around with it. you push F7 to spawn where ever the "yellow ball" is.
You can also press Ctrl + A when your admin, to bring the admin menu, where you can click on a player name, and click the spy button.
Than, you will see the player you are spying, and you can rotate the cam around them using the mouse.
The player cannot see you when your doing this, and no "yellow ball" shows up.