> For the complete documentation index, see [llms.txt](https://docs.parallels.com/landing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/readme/about-parallels-ras.md). # About Parallels RAS Parallels RAS provides vendor independent virtual desktop and application delivery from a single platform. Accessible from anywhere with platform-specific clients and web enabled solutions, like the built-in Parallels Web Client, Parallels RAS allows you to publish remote desktops, applications and documents, improving desktop manageability, security and performance. Parallels RAS extends Windows Remote Desktop Services by using a customized shell and virtual channel extensions over the Microsoft RDP protocol. Parallels RAS supports all major hypervisors from Microsoft, VMware, and other vendors including Hyperconverged solutions such as Nutanix AHV (AOS) and Scale Computing and Cloud platforms and services such as Microsoft Azure and Azure Virtual Desktop (formerly known as Windows Virtual Desktop), enabling the publishing of virtual desktops and applications to Parallels Client. The product includes powerful universal printing and scanning functionality, as well as resource-based load balancing and management features. With Parallels Device Manager Module for Parallels RAS you can also centrally manage user connections and PCs converted into thin clients using the free Parallels Client. ## **How does it work?** When a user requests an application or a desktop, Parallels RAS finds a least loaded RD Session Host or a guest VM on one of the least loaded Providers and establishes an RDP connection with it. Using Microsoft RDP protocol, the requested application or desktop is presented to the user. Note that in addition to RD Sessions Hosts and VDI, Parallels RAS can also be used to configure, manage and publish Azure Virtual Desktop resources. Users can connect to Parallels RAS using Parallels Client (available at no charge), which can run on Windows, Linux, macOS, Android, Chrome, iOS and iPadOS. Users can also connect via an HTML5 browser or Chromebook. As newer versions of Windows keep on being developed as time goes by, you need to defend the migration cost to your business. Parallels RAS can help. Desktop replacement allows you to extend the lifespan of your hardware and delay migration to the latest OSs to a time that suits you best. The Parallels RAS solution allows you to be very flexible: you can lock machine configurations on the user side, placing your corporate data in an extremely secure position; or you can opt to allow users to run some local and remote applications. Parallels Client Desktop Replacement is able to reduce the operability of the local machine by disabling the most common local configuration options, while guaranteeing the same level of service and security afforded by thin clients, directly from your existing PCs. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/readme/about-parallels-ras.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.