A workstation motherboard is usually designed for more robust applications/environments (very similar to server motherboards). They are built to be more reliable and upgradable. They typically support more RAM sockets, error correcting RAM (ECC), 2 or more CPU sockets, more expansion sockets, better power regulation, and basically higher quality components. They tend to be expensive, and you will pay more for RAM if it requires ECC memory. You will likely not find much overclocking support, since they designed for reliability.