Virtual desktop infrastructure (VDI) is a way of running users’ desktops, usually Windows with their applications, as virtual machines on central servers, and streaming the screen to whatever device the user connects from. The operating system, applications and primary data can remain centrally hosted in the data center or cloud; the user’s device sends keystrokes and mouse movements and displays the result. Whether copies of data reach the device depends on how the platform is configured. VDI is infrastructure you or a partner build and run, which distinguishes it from desktop as a service, where a provider runs the platform for you.
At a glance
- Desktops run as virtual machines on servers you control, in your data center, a colocation facility or cloud infrastructure.
- Users connect from thin clients, laptops, tablets or browsers; applications and primary data can remain centrally hosted, but keeping copies off devices takes configured controls.
- Core components are a hypervisor, a connection broker, desktop images, storage and a display protocol.
- User experience depends heavily on network latency and on correct sizing of compute, storage and graphics.
- VDI centralizes control but adds infrastructure, licensing and specialist administration; it is not automatically cheaper or more secure, and on its own it is not a data-loss control.
What problem it solves
Traditional desktops put the operating system, applications and data on each device. Every laptop must be patched, protected and supported individually, and a lost or stolen device can expose data. Giving contractors, offshore teams or remote staff access to sensitive systems often means either shipping managed hardware or trusting unmanaged personal devices.
VDI moves the desktop into the data center. IT patches and updates a smaller number of standard images rather than hundreds of devices, and users get the same desktop from any location. Because applications and primary data can remain centrally hosted, a lost device can expose less, and access can be cut off in one place. That depends on configuration: preventing local copies requires controls over clipboard, drive mapping, printing, downloads, local caching and access from unmanaged devices. When an office or a laptop is lost, users can usually reconnect from another device and keep working, which also makes VDI useful in continuity planning.
How it works
Hypervisor and hosts. Servers run a hypervisor that divides their CPU, memory and storage among many virtual desktops. Hyper-converged infrastructure, which combines compute and storage in one cluster, is a common platform for VDI.
Desktop images and pools. Administrators maintain a small number of standard images. Desktops can be persistent, where each user keeps their own virtual machine, or non-persistent, where users get a fresh desktop from a shared pool each session, with profiles and data stored separately.
Connection broker. The broker authenticates users, often with multi-factor authentication through the company identity provider, and assigns them a desktop according to policy.
Display protocol. A remote display protocol, such as RDP or a vendor’s own protocol, compresses the screen and sends it to the user, while sending input back. Graphics-heavy users may need GPU-equipped hosts.
Endpoints. Users connect from client software, a browser or a thin client. Session-based alternatives let many users share one server operating system, which is denser but less isolated than one virtual machine per user.
When it matters for buyers
- When giving third parties or remote staff access to sensitive systems. Applications and primary data can stay centrally hosted and access is controlled in one place, provided clipboard, drive mapping, printing, download and unmanaged-device controls are configured.
- When desktop support costs are high. Standard images can reduce per-device work, though the platform itself needs skilled administration.
- When a hardware refresh is due. Thin clients or older laptops can serve as endpoints, which changes the refresh budget.
- When choosing between building and buying. Owning VDI gives control over performance and data location; DaaS shifts operations to a provider.
- When regulated data is involved. Centralizing data can help with safeguards in frameworks such as HIPAA or PCI DSS, but it does not make an environment compliant by itself.
VDI usually runs on hyper-converged infrastructure or private cloud platforms sized for desktop workloads.
Questions to ask vendors
- How many users per host does your design assume, and what testing supports that figure?
- How do you handle users who need graphics acceleration or heavy applications?
- Which Microsoft and platform licences are required, and who supplies them?
- What latency and bandwidth do users need for a good experience, and how is it monitored?
- How are user profiles, data and printing handled in non-persistent pools?
- How is access secured, and does it integrate with our identity provider and MFA?
- Which controls for clipboard, drive mapping, printing, downloads, local caching and unmanaged devices are available, and how are they set by default?
- What does recovery look like if a host, cluster or site fails?
How it differs from DaaS
Desktop as a service (DaaS) delivers the same kind of virtual desktop as a subscription service. The provider runs the brokers, hosts and management platform, and you typically pay per user per month. With VDI, you or your integrator build and operate the platform, either on-premises or on cloud infrastructure you control, and you carry the hardware or cloud costs, licensing and administration. VDI gives more control over performance, data location and customization; DaaS reduces the infrastructure your team must run and turns it into an operating expense. Some products blur the line by offering a cloud-managed control plane with desktops running on your own infrastructure, so check who operates each layer.
Problems this helps with
- Contractors and remote staff need access to sensitive apps while limiting what data reaches their laptops
- Patching and supporting hundreds of individual PCs
- Apps that only run on Windows desktops but users work from anywhere
- Getting staff working again quickly when an office or device is lost
