A matter of perspective.
I don't use the word backup any more; when people do they get my lecture on the Four Rs of data copy usage. Because there isn't ONE reason why we take copies, or replicas, or backups, or whatever you wish to call them, there are four!
As all the smart people have recognised already, what matters isn't that a copy is made. What matters is what you want to do with it afterwards. And it ain't so simple once you get beyond protecting your email and photo albums.
So the Four Rs of data copy usage are:
* Restore. Pull back one or more historical files, tables, volumes or what have you because the current working set was deleted or corrupted.
* Recover. Restart data processing using an alternate facility due to loss of a primary.
* Repurpose. Use a primary data set for production support, report generation, system test, or system development.
* Retain. Meet regulatory and legal requirements - and broader expectations - for data archival and discovery.
The interest in each outcome should guide you as to which storage technology capabilities to buy or build. Some are surprised to learn that traditional tape backup is not the best path to achieving all four at efficient cost in one package.
I've heard the phrase "Information Lifecycle Management" (ILM) used when introducing this topic, but I avoid doing so because it's an industry term and everyone else glazes over. Even your IT colleagues will look at you funny, suspecting a dose of Gartner kool-aid. To be fair, ILM "done right" is a bigger topic, encompassing people and process as well as technology: it is comparable to ITSM, PM and the SDLC as a complete subdiscipline of ICT. It is well worth treating as a separate competency once you have some scale.