Application virtualization is a process that deceives a standard app into believing that it interfaces directly with an operating system's capacities when, in fact, it does not. 

This ruse requires a virtualization layer inserted between the app and the OS. This layer, or framework, must run an app's subsets virtually and without impacting the subjacent OS. The virtualization layer replaces a portion of the runtime environment typically supplied by the OS, transparently diverting files and registry log changes to a single executable file.

By diverting the app's processes into one file instead of many dispersed across the OS, the app easily operates on a different device, and formerly incompatible apps can now run adjacently. 

Used in conjunction with application virtualization is desktop virtualization—the abstraction of the physical desktop environment and its related app software from the end-user device that accesses it.

Application (and desktop virtualization) are a Desktop as a Service (DaaS) managed by a hypervisor (aka virtual machine monitor or VMM). A VMM infrastructure—software, firmware, and/or hardware—creates and operates virtual machines (VMs). A host (server) connects to multiple guests (endpoints). 

Application and desktop virtualization enables centralized management of the complete desktop environment ecosystem. Organizations need only to patch but a few images of applications and virtualized desktops rather than a myriad of endpoints, thereby deploying updates consistently, completely, and rapidly.

Since software and security updates are stored on images in data center servers, endpoint device exposure to vulnerabilities such as nascent malware or app manipulations is significantly reduced. 

These server images facilitate regulatory compliance with standards such as the Payment Card Industry Data Security Standards (PCI DSS) and the Health Insurance Portability and Accountability Act (HIPAA). Since data is not processed or stored on endpoint devices, no data breach occurs, should the device become compromised. The endpoint device is but a display terminal.

Application and desktop virtualization both support incident management, resolving many adverse desktop events by merely refreshing a virtualized image, and restoring the desktop environment to its previous state.

Other virtualization benefits include:

• Allows the running of legacy apps (e.g., those developed for end-of-life OS platforms like Windows 7 and XP).
• Enables cross-platform operations (e.g., running Windows apps on iOS, Android, macOS, and Chrome OS).
• Prevents conflicts with other virtualized apps (e.g., conflicting anti-malware software).
• Permits users to run multiple app instances—if not virtualized, many apps can detect the running of an instance and won't allow new ones.

However, some apps pose challenges to virtualization. For example, an application requiring a device driver (which integrates into the OS and is thus OS-specific) can affect the use of peripherals like printers.

Also, 16-bit applications and apps requiring extensive OS-integration are problematic to virtualize (e.g.,  some anti-virus programs). Latency caused by virtualization can drag graphics-intensive apps during the rendering process.