UNC is a naming convention used primarily to specify and map network drives in Microsoft Windows. Support for UNC also appears in other operating systems via technologies like Samba. UNC names are most commonly used to reach file servers or printers on a LAN.

UNC Name Syntax

UNC names identify network resources using a specific notation. UNC names consist of three parts – a server name, a share name, and an optional file path. These three elements are combined using backslashes as follows:

\\server\share\file_path

The server portion of a UNC name references the strings maintained by a network naming service such as DNS or WINS. Server names are set by a system administrator.

The share portion of a UNC name references a label created by an administrator or, in some cases, within the operating system. In most versions of Microsoft Windows, for example, the built-in share name admin$ refers to the root directory of the operating system installation (usually C:\WINNT or C:\WINDOWS).

The file path portion of a UNC name references the local subdirectories beneath the share point.

UNC Name Examples

Consider a standard Windows XP computer named teela. In addition to the built-in admin$ share, say you have also defined a share point called temp that is located at C:\temp. Using UNC names, you would connect to folders on teela as follows:

• \\teela\admin$ (to reach C:\WINNT)
• \\teela\admin$\system32 (to reach C:\WINNT\system32)
• \\teela\temp (to reach C:\temp)

Using Windows Explorer or the DOS command prompt, and with proper security credentials, you can map network drives and remotely access folders on a computer by specifying the UNC names.