The definition of hybrid cloud seems to be evolving significantly from what it was a few short years ago. But cloud computing is still in its infancy technically speaking, the progress of cloud will depend significantly on improved security and application monitoring for services which reside off premise:
In my humble opinion, I believe that a hybrid cloud has evolved away from its original definition, in that I believe a better definition would be, “A hybrid cloud is any cloud that uses multiple technologies.” The technologies could be VMware’s vSphere and or Microsoft’s HyperV with a touch of Citrix Xen Server. Would this not also be a hybrid solution, even though there is no public cloud presence? This is where I believe we have evolved, and we should reconsider how we define a hybrid cloud. Or, we could look into defining what a private, multiple hypervisor solution should be called.
You can read more here: How Do You Define a Hybrid Cloud?