While a traditional thin client is streamlined for multi-protocol client-server communication, a zero client has a highly tuned on board processor specifically designed for one possible protocol (PCoIP, HDX, RemoteFX, DDP). A zero client makes use of very lightweight firmware that merely initializes network communication through a basic GUI (Graphical User Interface), decodes display information received from the server, and sends local input back to the host. A device with such simple functionality has less demand for complex hardware or silicon, and therefore becomes less prone to obsolescence. Another key benefit of the zero client model is that its lightweight firmware represents an ultra-small attack surface making it more secure than a thin client. Further, the local firmware is so simple that it requires very little setup or ongoing administration. It's the ultimate in desktop simplification but the trade-off is flexibility. Most mainstream zero clients are optimized for one communication protocol only. This limits the number of host environments that a zero client can provide its users with access to.