Distributed rendering is a way to spread the process of rendering across one or several computers connected to a network. This, in turn, makes more use of idling computers and could reduce the time it takes for renderings to complete. One scenario could be a dealership that purchases a really powerful computer designated for rendering, and then have all staff computers connect to that machine.
In CET Designer, this is implemented through two components; CET Designer equipped with the Render Accelerator Extension (clients) that you can purchase here, and a small freestanding application (the CET render server) that you install on each computer that should serve as a resource in the rendering network. Installing the render server is free for as many computers as you like and it doesn’t require CET Designer or a license, and you can download it from here: http://www.configura.com/cet/support/downloading-the-render-accelerator-installer/