A blade server is one or more processors and some memory mounted on a
board that plugs into a standard chassis. As more and more blades are plugged in, the chassis becomes more powerful.
Because of their sparse configuration, more blades can fit into a given space than conventional servers can. Although details vary, many blade servers are designed so that multiple servers can share a single network connection, power supply, storage system and set of input/output devices. That means less hardware has to be mounted on or connected to each blade.
Blades are designed so that one can immediately take over for another that fails. They also usually are hot-
swappable, so that one can be physically unplugged from the rack and replaced with a new one with no disruption in operations.