NTFS reparse point

An NTFS reparse point is a type of NTFS file system object. It is available with the NTFS v3.0 found in Windows 2000 or later versions. Reparse points provide a way to extend the NTFS filesystem. A reparse point contains a reparse tag and data that are interpreted by a filesystem filter identified by the tag. Microsoft includes several default tags including NTFS symbolic links, directory junction points and volume mount points. Also, reparse points are used as placeholders for files moved by Windows 2000's Hierarchical Storage System. They also can act as hard links, but aren't limited to point to files on the same volume: they can point to directories on any local volume.

Design

In general:

Soft links

Windows Vista supports a new symbolic link capability that replaces junction points in Windows 2000 and Windows XP. They are designed to aid in migration and application compatibility with UNIX operating systems. Unlike a junction point, a symbolic link can also point to a file or remote SMB network path. Additionally, the NTFS symbolic link implementation provides full support for cross-filesystem links. However, the functionality enabling cross-host symbolic links requires that the remote system also support them, which effectively limits their support to Windows Vista and later Windows operating systems.