"A snapshot is a view of information at a particular point in time." (Claudia Imhoff et al, "Mastering Data Warehouse Design", 2003)
"A database dump or the archiving of data out of a database as of some moment in time." (William H Inmon, "Building the Data Warehouse", 2005)
"A database snapshot is a moment-in-time recording of a database and keeps track of every change made to a database from the moment the snapshot was taken. This method often prevents user mistakes as an add-on to fault-tolerance." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)
"A feature of SQL Server 2005 that enables you to indefinitely store the state of the database at a particular point in time." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)
"A new feature of SQL Server 2005 where a snapshot of a database can be created at any given time to preserve the state of the database. The snapshot can be queried if desired and/or the entire database can be restored from the snapshot." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)
"The state of an object, a system, or a collection of attributes regarding a state at a particular point in time." (DAMA International, "The DAMA Dictionary of Data Management", 2011)
"A read-only, static view of a database at the moment of snapshot creation." (Microsoft, "SQL Server 2012 Glossary", 2012)
"A copy of a data structure at some point in time" (Nell Dale et al, "Object-Oriented Data Structures Using Java" 4th Ed., 2016)
"A record of the current state of the database environment." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)