Microsoft cloud
VDI
Virtual Desktop Infrastructure
Virtual Desktop Infrastructure, universally abbreviated VDI, is the general architecture of hosting desktop operating systems and applications on centralised servers rather than on the physical devices end users hold.
Why VDI matters in a Microsoft estate
VDI matters because Microsoft 365, Azure, Windows 365, Teams, and related services are usually managed as one estate. The term connects to planning, cost, configuration, security, and day-two operational decisions across that estate.
How VDI shows up in practice
Users connect remotely over a display protocol to a virtual machine that behaves, from their perspective, like a local desktop. The concept predates the current cloud era by well over a decade, originating with on-premises solutions like Citrix XenDesktop and VMware Horizon. These required an organisation to own and operate its own hypervisor infrastructure, storage, and networking to host the virtual desktops, giving full control but also full responsibility for capacity planning, patching the hypervisor layer, and disaster recovery. Microsoft's cloud-native entries into this space, Azure Virtual Desktop and Windows 365, are best understood as VDI delivered as a managed or fully managed service, rather than a fundamentally different technology.
Azure Virtual Desktop runs on Azure infrastructure the organisation still configures and manages directly, including session host pools, host scaling, and image management. Windows 365 abstracts nearly all of that away into a fixed per-user, per-month Cloud PC subscription, with Microsoft handling the underlying host infrastructure. The core VDI trade-off that has held constant across two decades of implementations is cost and control versus operational simplicity. Traditional on-premises VDI offers the deepest customisation and can be cheaper at very large, steady-state scale, but demands significant in-house virtualisation expertise and up-front capital investment. Cloud VDI models trade some of that control for consumption-based or fixed pricing and dramatically reduced infrastructure management overhead instead, which is why most net-new VDI deployments today default to Azure Virtual Desktop or Windows 365 rather than standing up new on-premises hypervisor farms.
A persistent point of confusion in the market is using "VDI" and "Windows 365" interchangeably. Windows 365's fixed-cost, always-on Cloud PC model is deliberately simpler and less configurable than the session-pool, autoscale, multi-session VDI model that Azure Virtual Desktop and traditional on-premises platforms use. Choosing between them is a genuine architectural decision driven by use case: task workers and predictable headcount suit Windows 365's flat pricing, while variable or burst capacity, kiosk-style multi-session hosts, and highly customised desktop images tend to be better served by Azure Virtual Desktop's more granular control over host pools, scaling plans, and session density.