Hi,

A database snapshot is not a backup, it is just an "empty" database that holds the changes in the source database pages and during time it grows as more transactions commit.

Here are some links: http://www.sqlservercentral.com/articles/Disaster+Recovery+(DR)/2598/

http://blog.sqlauthority.com/2010/04/05/sql-server-2008-introduction-to-snapshot-database-restore-from-snapshot/

Regards

IgorMi