Noise is a random variation that is present in any analog signal. Digital camcorders are still vulnerable to video noise because it occurs between the CCD and the analog to digital converter. Noise can create unwanted artifacts on digital pictures and video. Noise increases in proportion to the temperature (higher temperature means more noise). Noise is more present on smaller CCDs, and at lower exposure or lower light levels. The quality of the CCD is also important to preventing noise.
Noise can be lessoned after the video has been taken with noise reduction filters. Noise reduction works by blurring the image, adveraging out near pixels. This also makes edges less sharp, so there is usually an option to only blur pixels that are close in color to eachoter.