PCoIP is a remote display protocol for delivering remote desktops and applications.
PC over IP uses the User Datagram Protocol (UDP), an alternative to the Transmission Control Protocol (TCP). PCoIP delivers bitmaps by encoding them on a remote host and then streaming the data to the client, transmitting only regions of the screen that change from frame to frame. From the client perspective, it's almost as if the client is watching a movie of the desktop's activities that's being created in real time. PCoIP can handle multimedia and graphics-heavy applications, but it does increase the CPU load on the remote host.
PCoIP is a proprietary protocol invented by Teradici Corp.