What is ExpressCard?
An ExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. ExpressCards is a hardware standard replacing PC cards or PCMCIA cards. The host device supports both PCI Express and USB 2.0 connectivity through the ExpressCard slot.
The Expresscard module comes in two sizes. Expresscard/34 is 34 mm wide, while the Expresscard/54 is 54 mm wide. The modules are both 5 mm high and 75 mm long. The 34 mm module has the advantage in that it can fit into the slot designed for the 54 mm card, but not vice versa.
The Expresscard simply slots into a USB interface that is already integrated on most desktop computers and notebooks.
ExpressCard slot are hot-pluggable, which means they can be activated by connecting them directly without shutting down the computer.