DiskScripts: .scr Suffix On Downloaded Files

I just downloaded a file from one of Apple's software update sites. The filename has the suffix ".scr". What type of file is this?
The .scr suffix stands for script. More specifically, they are files containing scripts used by the Disk Copy utility program. These scripts are referred to as DiskScripts.

A DiskScript is a special file containing commands that instruct Disk Copy 6.1 or later to perform an action on a list of disk images, and to optionally launch an application with or without a specific document. DiskScripts are not related to, and do not require AppleScript to run.

Executing a DiskScript
Published Date: Feb 18, 2012