Hidden shares are characterized by the “$” at the end of the shares name.
If you do a \\computername\ , you will not see the hidden shares. However if you do a \\computername\C$ , you will be able to see the content of the C drive ( if you have proper access) because the C drive is a hidden share.
To get more info about a hidden share, visit the Microsoft link referenced below.
Reference
http://support.microsoft.com/kb/314984