Version - The Version number is used to specify the database version being used and is generally changed when there is a change in functionality or when new functionality has been added. 

Build - The Build number is updated with every product release and is generally changed with minor functionality changes.

Revision - The Revision number is used to track the version of the cumulative patch that is installed.

For example, The Raiser's Edge 7.91.5056.25 (version 7.91, build 5056, patch 25)

For more information on finding the version of your software, please review Knowledgebase solution: How to find the software version and/or patch number (BB79245)