The construction of a condenser microphone must include some provision for maintaining the electrical charge.
An “electret” condenser microphone has a permanent charge, maintained by a special material such as Teflon deposited on the backplate or on the diaphragm.
Other types are charged by means of an external power source. All condenser mics contain additional circuitry to match the electrical output of the element to typical mic inputs.
This requires that all condensers be powered: either by batteries or by “phantom” power (a method of supplying power to a mic through the mic cable).
There are two potential limitations of condenser mics due to the additional circuitry: first, the electronics produce a small amount of noise; second, there is a limit to the maximum signal level that the electronics can handle.
Good designs, however, have very low noise levels and are also capable of very wide dynamic range.
Condensers are more complex than dynamics and tend to be somewhat more costly. However, they can readily be made with higher sensitivity and provide a smoother, more natural sound, particularly at high frequencies.
Flat frequency response and extended frequency range are also much easier to obtain in a condenser. And, condenser mics can be made very small without significant loss of performance.
The decision to use a condenser or dynamic depends not only on the sound source and the signal destination but on the physical setting as well.
From a practical standpoint, if the mic will be used in a more “severe” environment such as a fellowship hall or for outdoor sound, a dynamic microphone is a good choice.