Shadow Copy (Volume Snapshot Service or Volume Shadow Copy Service or VSS), is a technology included in Microsoft Windows that allows taking manual or automatic backup copies or snapshots of data, even if it has a lock, on a specific volume at a specific point in time over regular intervals. It is implemented as a Windows service called the Volume Shadow Copy service. A software VSS provider service is also included as part of Windows to be used by Windows applications. Shadow Copy technology requires the file system to be NTFS to be able to create and store shadow copies. Shadow Copies can be created on local and external (removable or network) volumes by any Windows component that uses this technology, such as when creating a scheduled Windows Backup or automatic System Restore point.

VSS operates at the block level of the file system.

Snapshots have two primary purposes: they allow the creation of consistent backups of a volume, ensuring that the contents cannot change while the backup is being made; and they avoid problems with file locking. By creating a read-only copy of the volume, backup programs are able to access every file without interfering with other programs writing to those same files.

The Shadow is a collection of serialized dramas, originally in pulp magazines, then on 1930s radio and then in a wide variety of media, that follow the exploits of the title character, a crimefighting vigilante in the pulps, which carried over to the airwaves as a "wealthy, young man about town" with psychic powers. One of the most famous pulp heroes of the 20th century, The Shadow has been featured in comic books, comic strips, television, video games, and at least five motion pictures. The radio drama is well-remembered for those episodes voiced by Orson Welles.

Introduced as a mysterious radio narrator by David Chrisman, William Sweets and Harry Engman Charlot for Street and Smith Publications, The Shadow was fully developed and transformed into a pop culture icon by pulp writer Walter B. Gibson.

The Shadow debuted on July 31, 1930, as the mysterious narrator of the Street and Smith radio program Detective Story Hour. After gaining popularity among the show's listeners, the narrator became the star of The Shadow Magazine on April 1, 1931, a pulp series created and primarily written by the prolific Gibson.