A keypad structure with a backlight source includes a base, a light guiding plate, a thin film circuit board, a resilient component, a keycap, and an elevating mechanism. A power unit comprises first and second power circuits. A surface of the cage contacting the vertebrae has an undulating shape for limiting sliding of the cage in a plane parallel to the vertebrae faces. The plugins andor login candidates can allow the framework to pluggably and dynamically recognize and log into various types of computer resources. Once the card edge is inserted into the socket of the card edge connector, the socket allows for rotation of the daughter card about the received card edge.