Hyper convergence

Hi
I have confusion about hyper-convergence.
I have read that it is a software defined infrastructure that integrate compute,networking,storage,virtualization in one node.
If so, what is difference between openstack software and software that enable hyper convergent ?
Openstack can manage compute,storage,networking to include in one node at software layer.
I still do not know what hyper convergence actually do .
Please explain me to be clear