What are expansion bays?
An expansion bay provides space, and possibly power, system connections and cooling to accommodate extra peripherals in your system. In a desktop computer it would be the area withe PCI/PCIx slots and the drive bays. In a laptop, it might be a slot where to can insert/swap optional components such as batteries, cd/dvd drives and floppies. Some docking stations may have an expansion bay where the bus is brought outside of the laptop, enabling you to plug-in regular expansion cards. This illustration is Dell Latitude C/Dock II. It has an expansion bay with 2 PCI slots. It also has connections for monitor, network, serial, parallel, USB, speakers, power etc. allowing you to simply slide the laptop into the base when you return to the office without having to reconnect cables. Sources: http://www.bobjohnson.com/_store/Display_Buy.asp?
