 system made for safety purposes. [Computer and Information
Sciences] 
v., To make a copy of all or portions of software or data files on a system on storage media or on a separate system for safety
n., The ability of a software application or a system to share data or commands with older versions of itself, or sometimes other older applications or systems, particularly applications or systems it intends to supplant. Sometimes backward compatibility is limited to being able to read old data but does not ext