At the heart of the technology is a mechanism called the CCD, or charged coupled device. The CCD is a light-sensitive chip that acts like film by capturing the image in the lens on a matrix of photoreceptors or pixels. The Hubble Space Telescope uses a CCD to capture images from deep space, so this is a fairly sophisticated piece of equipment. Optimally, you'd like a CCD with 680,000 pixels, but these generally represent the high end of the consumer camcorder market. Many come with between 360,000 and 390,000, which is fine.
Camcorders come with both optical and digital zoom features.
The optical zoom enlarges images with a lens, the same way traditional cameras do, while the digital zoom simply enlarges the pixels in the center of the picture frame. Some camcorders come with digital zooms of 400X or more, but experts say such a powerful zoom is not necessary for amateurs. When evaluating a camcorder's ease of use, consider how you'll view what you're recording. The LCD viewfinders give you a much better picture of what your video will actually look like. Typically, LCDs are 2.5 to 3.5 inches.