server blade
A server blade is a thin, modular electronic circuit board containing one, two, or more microprocessors and memory, that is intended for a single, dedicated application (such as serving Web pages) and that can be easily inserted into a blade server, which is a space-saving rack with many similar servers.
One product offering, for example, makes it possible to install up to 280 blade server modules vertically in multiple racks or rows of a single floor-standing cabinet. Blade servers, which share a common high-speed bus, are designed to create less heat and thus save energy costs as well as space.
Confusingly, individual blades are also sometimes referred to as "blade servers."