What is a Virtual Machine?

A virtual machine (VM) is a virtual environment that works like a computer within a computer. It runs on an isolated partition of its host computer with its own resources of CPU power, memory, an operating system (e.g. Windows, Linux, macOS), and other resources. This allows end-users to run applications on VMs and use them as they normally would on their workstation.

How do Virtual Machines work?

VMs are made possible through virtualization technology. Virtualization uses software to simulate virtual hardware that allows multiple VMs to run on a single machine. The physical machine is known as the host while the VMs running on it are called guests.

Why should businesses use Virtual Machines?

Resource and cost efficiency Scalability Security Cloud computing

How Citrix helps your business with virtualization?

Citrix Virtual Apps and Desktops gives your organization the tools it needs to benefit from virtualization software. Access business apps and virtual desktops on any device seamlessly. Enjoy fast, lag-free user experiences powered by Citrix’s high-definition experience (HDX) technology. Leverage Microsoft’s full suite of products—from Azure to Teams and Office 365—in your VDI deployments. Maintain business continuity by establishing productive and secure virtual workspaces for employees to work anywhere.

What is a virtual desktop?

A virtual desktop is a software emulation of a hardware device in which the end-user desktop runs on a physical or virtual machine at a remote location that may be hosted on premises or in the cloud. Virtual desktops enable end users to access their unique desktop environment, including operating system and applications, remotely over a network, through client software or a web browser on the endpoint device of their choice.

Types of virtual desktops

Virtual desktops rely on a technology called desktop virtualization, which separates the desktop environment and its applications from the physical device used to access it. The primary types of desktop virtualization are determined by whether the operating system runs on local hardware or remotely. Although local desktop virtualization allows offline access, remote desktop virtualization is more common (and the focus of this page) because it offers key advantages for connecting to operating systems and applications, including:

Support for a wide array of endpoint devices including standard PCs and laptops as well as low-cost thin clients and mobile devices
Secure data storage in the data center or cloud with only keystrokes and clicks transferred from the endpoint device
Support for a greater number and types of desktops than would be possible on most local devices alone
Centralized management and control for data, settings, and more
Device agnosticism, which minimizes impact when devices are lost, stolen, or malfunctioning
The ability to seamlessly roam sessions from one device to another in real time

Remote virtual desktops are traditionally delivered through Microsoft Remote Desktop Services (RDS) as the underlying technology. RDS, formerly known as Terminal Services, was based on software from Citrix Systems. A single operating system instance installed on a server is shared by multiple remote users connecting over a network. Virtual applications and desktops are then displayed on client devices through a special set of data transfer rules defined within a remote display protocol. With RDS, the Microsoft Remote Desktop Protocol (RDP) is used to access a shared group of servers based on a consistent virtual machine image within one or more resource pools. With Citrix, the Independent Computing Architecture (ICA) protocol is used to access virtual desktops across a broad range of scenarios.

Virtual desktop infrastructure (VDI) is another variation of the client-server model of desktop virtualization in which desktop operating systems run inside a virtual machine on on-premises servers or within a public cloud. With VDI, users access individual desktops, and the applications that reside on them, in a 1-to-1 mapping. Windows 10 Enterprise multi-session is an exception, though, as it’s an Azure-only version of Windows 10 that accepts multiple simultaneous user connections. For customers who desire a more turnkey and managed solution for their VDI environment, desktop as a service (DaaS) is a VDI delivery model from the cloud, offering managed services and other features designed to simplify onboarding and maintenance.

How virtual desktops work

Virtual desktop infrastructure uses virtual machines to deliver virtual desktops to a variety of connected devices and is implemented in two primary ways: persistent and non-persistent.

With a persistent virtual desktop, each user has a unique desktop image dedicated to them that they can customize with apps and data. All applications and files are stored across reboots and the user’s settings are preserved and appear at each login. This consistency provides a similar experience to a physical PC environment which eases user adoption and is well-suited to power users. Individual customized virtual desktops do require different lifecycle management considerations for storage and software updates compared with non-persistent virtual desktops.

A non-persistent virtual desktop infrastructure allows users to access a virtual desktop from an identical pool of available desktops. Non-persistent virtual desktops are clones of a shared golden desktop image where users receive a fresh instance every time they log in. Non-persistent virtual desktops are personalized through user profiles, scripts, or special software. Any customizations that users make within their sessions, such as installing apps, is discarded. Less storage is required, as user configuration settings and data are stored separately, and once the user logs out of their session, the virtual machine reverts back to its base image state ready to accept connections from another user. Non-persistent desktops are easier for administrators to manage the lifecycle as the underlying image remains consistent. For this reason, non-persistent desktops are often more popular than persistent desktops.

In VDI, the creation of multiple virtual machines from a single physical machine is handled by software called a hypervisor in on-premises environments. The hypervisor provides operating system isolation, intercepting the commands sent to the underlying hardware. It enables multiple operating system instances, through the use of virtual machines (VMs), all sharing a single hardware platform. Within public clouds, the hypervisor and underlying infrastructure are abstracted, and administrators work directly with the virtual machines and cloud-native actions and APIs.

Because virtual machines perform just like physical machines while relying on the resources of only one computer system, virtualization allows IT organizations to run multiple operating systems on a single server or within a single public cloud account, from Microsoft Windows 10 or Windows Server 2019 to Linux and FreeBSD. The hypervisor or public cloud allocates computing resources, such as CPU, RAM, and disk space, to each virtual machine as needed. Server virtualization actually served as the foundation of cloud computing.

Why you need virtual desktops

Enabling remote work is a key consideration for many organizations focused on business continuity and employee productivity. Virtual desktops support enhanced mobility and remote access, allowing IT to deliver desktops securely to a wide variety of endpoints in any location. IT maintains centralized control of corporate resources and the ability to deploy them rapidly, while users have the flexibility to work on available devices and networks and to use cloud, web and mobile apps across multiple contexts on demand. Regardless of device, users have the same experience of their desktop and work environment each time they log in, a consistency that promotes productivity.

Virtual desktops also improve cybersecurity and reduce IT overhead. With data breaches becoming more frequent and costly, virtual desktop isolation and centralization is a critical factor in a multilayered security strategy. It also removes the risk of having sensitive corporate data stored locally on client devices.

Top benefits of virtual desktops

Virtual desktops offer significant advantages over physical desktop machines, especially:

Improved user experience: IT professionals tasked with setting up new desktops for employees or contractors can deliver a consistent experience across devices including PCs, tablets, smartphones and thin clients, giving employees and contractors a high degree of freedom in how they work The virtual desktop environment allows for personalization, so users may access a familiar experience of their “home” desktop from whatever client device they choose, including BYO devices.
Enhanced security: Virtual desktops offer significant security advantages. VDI allows for fine-tuned control and secure isolation of data, which is not stored on endpoint devices and therefore less vulnerable to theft. Since sensitive data remains in the data center, IT can perform audits and more easily control security incidents, which enables compliance that is especially important in highly regulated industries.
IT efficiency: Since the VDI environment is centrally managed from a data center or public cloud, administrators can apply software patches and updates, change configurations and enforce policies for all virtual desktops across the deployment. This isolated environment also enables developers to test applications without risk to the production environment.
Cost savings: Though users interact with applications on a virtual desktop as if they were on a physical device, virtual desktops are hosted inside virtual machines running on servers in an on-premises or cloud data center. Since the processing power happens in the data center, virtual desktop infrastructure enables organizations to choose lower-cost endpoint devices over high-performance desktop clients.
Scalability: A reliable VDI solution helps scale key applications and services to increasingly mobile users and remote teams. Whether staffing up temporarily, as in the case of seasonal workers or contractors, or making a permanent shift to a more distributed remote workforce, organizations can expand the VDI environment quickly, enabling users to be functional within minutes with immediate access to enterprise virtual desktop workloads and their respective apps.

Citrix solutions for virtual desktops

Provide the best VDI experience on any device or network

Citrix VDI solutions give teams reliable access to all the apps and information they need, whether they’re working in the office or thousands of miles from the data center. Users have access to a reliable, high-definition experience that helps them be productive at all times, and IT can lower costs and safeguard sensitive data by providing the right level of access to each user.

Get the most from your Microsoft investments

Citrix HDX optimizations and robust management tools extend the capabilities of Windows Virtual Desktop, an Azure-native remote desktop and application virtualization service that makes it easier to move desktop-based workloads into the cloud. A single Windows 10 virtual machine can host dozens of end user sessions, and Citrix deployment tools enable IT to reduce time to value and centrally manage both on-premises and Azure desktops.

Manage Windows and Linux virtual desktops side-by-side with Linux VDI support

With an increasing number of mission-critical apps running on Linux, the open-source operating system is playing an increasingly prominent role in the workplace. Linux VDI enables users to be as productive as possible, and with Citrix Virtual Apps and Desktops, administrators can deliver Linux virtual desktops in record time and manage them alongside Windows Virtual Desktops from a central console.