A junction, also called an NTFS junction point, is a feature of the NTFS file system. It is pointer to a directory on the local volume, similar to a symlink. It can be accessed through the Windows GUI in addition to the Windows command line. Junction points were first introduced with Windows 2000 and NTFS 3.0, and are supported in all subsequent versions of Windows.
Example of a junction point
Below is an example of a junction in the Windows command line.
Note: A junction cannot point to a remote share it must be a directory on the local volume. However, a symbolic link or symlink can point to a remote share.
What's the difference between a junction and a symlink (symbolic link)?
Although very similar, a junction is not the same as a symbolic link on a Windows computer. Below is a list of some of the major differences between a junction and a symbolic link.
- A junction point can only be a link to a local volume path. Symbolic links can be a local and remote path. For example, a symbolic link can link to the network share \\hope\files.
- A junction point is designed for local directories, but a symbolic link can be used for directories, files, and shares.
- A symbolic link resolves to the local machine. If you create a symbolic link to c:\hope on your computer and someone accessed that link from a remote machine, it would try to open c:\hope on their machine, not yours.
How to create a Junction in Windows
To create a junction point with Windows 2000, you can use the linkd program included with Windows 2000 and Windows 2003 Resource Kits or the junction tool released with Windows Sysinternals. Windows Vista, Windows Server 2008, and later versions of Windows include the mklink command for creating junction points.
How do I know if a directory or folder is a Junction point?
In the Windows command line
From the Windows command line, you can quickly identify if a directory is a junction when doing the dir command. As shown in the picture at the beginning of this page, if a directory is a junction shows as <JUNCTION> instead of <DIR> in the list of directory and files.
In Windows Explorer
In Windows Explorer, a junction point is a folder with a shortcut icon in the bottom left corner. In the picture to the right is a picture of a backup folder next to an example folder. The example folder is the junction that in this case points to the backup folder.