What is "Condenser Microphone"?
A microphone design in which the diaphragm is one plate of a capacitor and the back electrode is the other. It can either be externally charged or internally charged (electret microphone). A signal is generated whenever the diaphragm moves and the capacity is modulated. The capacity is typically in the range of 5-20 pF.
A condenser microphone always has a built-in amplifier to support a robust signal run in cables.