You don't need to use multiple employees to use a server. However, if you'd like to have different login/passwords, you would set that up via multiple employees. If you'd like, it could just be one password to login to the server. If you have multiple employees turned off and the server turned on, you can check "Require Password" and the client machines will need to type in your main password, set in the General pane of the Preferences window.
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