Unified communications is an evolving set of technologies that automates and unifies human and device communications in a common context and experience. It optimizes business processes and enhances human communications by reducing latency, managing flows, and eliminating device and media dependencies.
High Performance Computing (HPC) is accomplished by connecting many physical COTS (Commercial Off The Shelf) servers to create a larger logical computer.
Hyper-Converged Infrastructure (HCI) results from the use of a virtualization layer also known as a Hypervisor (Software Defined Computing), virtualized storage (Software Defined Storage), and a virtualized network (Software Defined Network).