Re: Software defined this, software defined that...
"Software Defined" originate from the idea you can use software abstractions (i.e. REST calls) to define infrastructure and services, SDN started with OpenFlow which allowed to bypass the rigid Cisco CLI based ACLs with something much more flexible and it controlled HARDWARE OR SOFTWARE, it evolved from there, many of the network services are now implemented in software to provide better flexibility.
the issue is that many guys in storage saw that as a marketing opportunity to re-brand their rigid/legacy products, and hijacked the term to mean "Software Implemented", useless term in days when ALL storage products run with software over x86.
the real software defined is AWS, which provide pretty high-level abstractions and automation on top of their infrastructure and services, in a way you dont even know or care how things are implemented. Check out the UI for most of the "Software-Defined" products, why is there so much data about low-level/infrastructure stuff and hardly any self-service abstractions ?