Microsoft Azure Stack HCI

Hyper-Converged Infrastructure (HCI) is a software-defined IT infrastructure that virtualizes all of the elements of conventional "hardware-defined" systems, such as compute, networking and storage. HCI is implemented via hypervisor platform, such as VMware vSAN, KVM or Microsoft Hyper-V for virtualized computing, software-defined storage, and virtualized networking. HCI is typically run on standard, off-the-shelf servers equipped with Direct-Attached Storage (DAS).

In simple terms, Cloud Computing is the delivery of computing services to a user or an organization—servers, storage, databases, networking, software, analytics, intelligence and more—over the Internet ("the Cloud"). Cloud Computing is usually provided using virtualization, in where the physical computer hardware is abstracted from the software & applications that are running on that hardware. Cloud Computing services can be provided several different ways, via public, private or hybrid clouds. Public cloud computing is provided by 3rd party service providers (such as Amazon Web Services, Microsoft Azure, or Google Cloud) who own the physical hardware and then sell these resources online via a secure internet connection. In a private cloud, an enterprise builds a cloud within their own data center by running applications on virtual servers that may reside on any number of available physical machines. Hybrid cloud computing is where a mixture of private and public cloud computing services are used together in tandem. As part of RightScale's 2018 State of the Cloud report, an in-depth survey was conducted of 997 IT professionals about their adoption of cloud infrastructure and related technologies, an astonishing 96% of respondents indicated that they run their enterprise's workloads in a cloud – either public, private or hybrid.

Software Defined Storage ("SDS") refers to the virtualization of storage systems, whereby the underlying storage hardware is abstracted from the storage software that manages it. SDS can be an element with a Software Defined Data Center or it can also function as a stand-alone technology. The software enabling the storage-defined storage environment may also provide policy management for features such as data de-duplication, replication, thin provisioning, snapshots and backup.

To scale horizontally is to scale out or in, and is defined as to add more nodes to or remove nodes from a system in a server, such is also explained as adding new computers to a distributed software application.

A Virtual Machine ("VM") is a software file, referred to as an image or an instance, which exhibits the behavior of a physical computer. Much like a physical computer, the VM runs an operating system and applications, and has its own virtual resources, including CPU, memory, hard drives, network interfaces, and other devices. Each VM's virtual resources are then mapped to the real resources on the physical host computer. A VM gives the end user the same experience as they would on the host itself, and single or multiple VMs can reside on the same host. For servers, multiple VMs run side-by-side with a piece of software called a hypervisor to manage them. The use of VMs to meet computing needs especially on the enterprise side is commonly referred to as virtualization.