Software defined storage is a programmatic approach to setting up and using storage. It allows you to use storage and expand by rational prediction of your needs. It is not a product, it is an approach made possible through connected hardware and software products. The details are not particularity important, but the connections between parts are quite loose.
Storage space is an issue in some ways. But as storage space becomes increasingly cheaper people tend to think the problems will solve themselves. There is some truth to this. Data does increase exponentially, but hardware manufacturers know this and are quick to produce larger capacity storage media because they know there is a growing market, and a profitable one at that. It is to their credit that the prices decrease as the capacity and performances increase.
If we’re on the Cloud we tend to think this is a pseudo problem; cloud is supposed to expand as the requirements increase. Well yes, if it has the software defined storage approach. Your data will accumulate, and if it’s anything like the past the increase will not be linear. We use to deal with megabytes. Now we buy Terabytes drives. The software defined storage approach should track this so we need never trash old customer files and always keep every email we ever received. We can be sure this will not level out in the future, but continue to expand even if your company stays at its present size forever (we actually hope your company does improve). The elastic approach of software defined storage predicts how this will expand so we need only buy the storage space we need. Yes, cloud can expand to accommodate our needs, that’s part of the appeal. But we need to know what are needs are, that’s part of the problem it wishes to address.