When installing Ubuntu, you are required to create one user account. That account is the “root” account, used to perform all administrative functions on the system. Any user with access to that account can modify or change any setting they want. Sometimes it necessary to create another account, say, for a guest, or for some one you want to use the computer briefly, but do not want to give them the power to make any changes to the default settings. To make it easier for you to manage such situations, you can create a guest account on the system, and make it available to your guest user.
To begin creating this account, launch the Users and Groups management tool from System > Administration > Users and Groups. Then click on the “Add” button.
On the “Create a new user” window, specify a generic name for the guest account (you can input a specific name). A generic login name will be automatically filled by the utility in the “Short name” box (change this if you want). It is not necessary, in my opinion, to encrypt the guest account’s home folder. Click “Ok.”
The next window that comes up is where you either specify the guest account password or have the tool generate one for you. Note that it is bad security practice to allow any user password-less access to your computer. Therefore, leave the “Don’t ask for password on login” unchecked. OK.
Now that the guest account has been created, you want to make sure that the account has the appropriate privileges you want assigned to it. Click on the “Advanced Settings” button to view the default settings.
In the “Advanced Settings” window, click on the “User Privileges” tab. This shows the default account privileges for the guest account. If you are satisfied with the default settings, click “OK.” But do you really want to allow a guest user access to system logs? My paranoid self wouldn’t.