The Internal Microphone

• All camcorders are fitted with an internal microphone that is already installed to pick up audio signals for recording. However, because camcorders are so small, their microphones tend to be very small as well and are tucked away among all the electronics. These are very simple microphones that pick up the sound waves and then transmit them to the recording. Because sound moves as an analog wave, these microphones can either transmit the sound directly or convert it to digital information.
  
  

External Microphones

• Because the internal microphone on camcorders is often insufficient for many people's needs, there are a variety of external microphones that can be purchased as accessories. For an external microphone to be equipped, the camcorder must have an audio input jack. Then, once the external microphone has been purchased, its plug will fit into the audio jack. Almost any microphone will work with any sort of camcorder as long as the plug for the microphone fits into the jack for the camcorder.
  
  

Types of External Microphones

• External microphones can be of almost any variety. Omnidirectional microphones are useful because they can pick up sound coming from any direction (and, in general, also record the direction from which the sound came). This offers an advantage over cheaper unidirectional microphones, which can only detect sound that is coming from the direction in which the microphone is positioned. Shotgun microphones are a type of microphone that is good at picking up sound from one specific location and filtering out all other sounds, which is useful if the event you are recording is not particularly near the camcorder. These microphones can also be positioned off of the camcorder to be closer to the sound source (particularly useful for recording someone's voice).