By default, if your computer is configured for file sharing, hidden share points known as 'Administrative Shares' are automatically created for each drive volume (C:\, D:\, etc.) on your computer. These share points are hidden because they have a dollar sign ($) appended at end of the share name. When another computer tries browsing the available shared resources on your computer any of the hidden share points will not be displayed.
To access these hidden share points from another computer you need to know the path of the hidden share on the remote computer. This path is known as the UNC (Universal Naming Convention), and it looks like this: '\\[computer_name]\[share_name]'.
For example, lets say there is a computer on your network called 'Computer-A', and lets say that 'Computer-B' was trying to get files from it. One of the ways to accessing a share point is by entering the UNC into the Run... command. So as long as the user on Computer-B has administrative rights to Computer-A, all that person would have to type is "\\computer-a\c$" in the Run... command and press the OK button. Then the explorer would open and display all the files on the C:\ drive of Computer-A.
If you want to hide any share points on your computer, all you have to do is append a dollar sign ($) to the end of the share name.