White balance basically means colour balance. It is a function which gives the camera a reference to "true white" — it tells the camera what the colour white looks like, so the camera will record it correctly. Since white light is the sum of all other colours, the camera will then display all colours correctly.
Most consumer-level camcorders have an "auto-white balance" feature, and this is how most amateurs operate. The camera performs it's own white balance without any input from the operator. In fact, very few home-video users are aware of it's existence. Unfortunately, the auto-white balance is not particularly reliable and it is usually preferable to perform this function manually.