Docking Connector
HINT: Docking devices may not be available in all countries.
Use this connector to attach the optional docking device, also called an advanced port replicator (APR). A docking device, or APR, allows you to easily use external devices with your computer, such as an external keyboard, mouse, or monitor.
See the documentation that came with your docking device for additional information.
PS/2 Connector
HINT: You can use the integrated keyboard and an external keyboard at the same time. When you attach a keyboard or numeric keypad, the integrated numeric keypad is automatically disabled.
Use this connector to attach
Shut down the computer before attaching or removing a
On an external keyboard, the 
key acts the same way as the 
key on the computer's keyboard (if the External Hot Key option is enabled in the system setup program).
USB Connector
Use this connector to attach USB devices, such as a mouse, keyboard, or printer.
Video Monitor Connector
Use this connector to attach an external monitor.
AC Adapter Connector
This connector attaches an AC adapter to the computer.
The AC adapter converts AC power to the DC power required by the computer. You can connect the AC adapter with your computer turned either on or off.
CAUTION: The AC adapter works with electrical outlets worldwide. However, power connectors and power strips vary among countries. Using an incompatible cable or improperly connecting the cable to the power strip or electrical outlet may cause fire or equipment damage.
NOTICE: When you disconnect the AC adapter from the computer, grasp the adapter cable connector, not the cable itself, and pull firmly but gently to avoid damaging the cable.