Optical zoom uses the camera's lenses to zoom in, and is far superior to digital zoom. Digital zoom uses the camera's software to try to magnify the image, sort of like using zoom when using Photoshop. Digital zoom shots usually end up looking blurry.

To clarify. Optical zoom is 'ajusting the lens' to get closer. A 1mp image sensor sees a smaller area of the image which translates to more detail for that area. Digital zoom is adding pixels using software. A 1mp is cropped to some fraction of the sensor so that the detail in that area is duplicated or dithered to approximate the detail. This translates to lower detail then optical zoom and usually looks 'fuzzy' Digital zoom is nearly worthless. Optical zoom is the only one you should pay attention to.

If you didn't understand what Ken just said... here's a extra-simplified version: Optical zoom is equivalent to you physically moving closer to the subject (although your lens does the moving not you) so you capture the actual image without any kind of digital manipulating on the part of your camera. The result is a clear shot, just like any other photo. Digital zoom is where the camera crops and enlarges the part of the photo you are trying to zoom in on. So it's not really a zoom, its just an enlargement. When you enlarge a photo, your camera has to make up the spaces in between the pixels (those tiny color blocks that make up the photo) that didn't exist in the original shot. The problem is that cameras aren't that smart, so the result is always blurry and sometimes discolored in areas because the camera's software duplicated the wrong pixels. This process is called dithering by the way, and there's more than one way to dither, but none of the dithering technologies is anywhere near being close to fooling the eye. That's why optical zoom is the only thing you should look at when considering a camera to buy.

To add to the other answers: Never use digital zoom. If you decide later that you actually only want that one part of the picture, you can always crop it and enlarge it on your computer. However, if you use digital zoom, and you later decide that you wanted the rest of the scene, then there's nothing you can do.

wow..ive been doing phoytography for over 20 years and didnt know this.. i have both on my cameras..never thought about it..great answers

Optical zoom is found on lenses that are used on 35mm type digital cameras. I.e. 25-100mm lens that "zooms" as most people say. Digital is done by the camera. Optical is far superior, hence you will pay a lot more.

Optical zoom means the lens only takes a photo of what you are zoomed in on. With digital zoom the photo is the same but it is cropped to appear as if it as optically zoomed in. The quality of digital zoom is only the quality of the tiny part of the image the crop was made from.

Optical zoom actually moves the lens so as to change the focus of the camera and hence focus on a different area of the scenery, hence zooming. Digital zoom just makes the picture bigger digitally. Think of it as this: Optical zoom is like using a magnifying glass where as digital zoom is like moving the picture closer to you. In short, optical zoom = great, digital zoom, for all intense and perpurses = useless.

Optical zoom is achieved by the lens and is the only way to get closer to the subject and retain all of the resolution. Digital zoom is manipulating the pixels in the image. Generally better done on the computer after downloading the pictures.

Digital sucks. Optical zoom is best. Digtal zoom is just cropping and enlarging the image. Optical zoom useses lens and optics to bring the image in closer with out a degradation of quality. Optical zoom is higher quality but requires large optics. Digital zoom is poor quality and requires no optics, digital is more like a simulated zoom. The best zoom lenses have very large pieces of glass to allow large amounts of light in. The crummiest lenses are small in diameter and produce poor quality images. Try it your self on your computer, take a very small image and enlarge it to full screen or in photoshop or irfanview select something like an eye and zoom in on it, you will see how the quality goes down. That is a digital zoom. General rule of thumb: The higher the megapixel camera, the larger the diameter the lens must be to compensate. This is especially true with very compact high megapixel cameras, they usually have pinhole sized lenses and allow for almost no light to enter; this results in a very crummy image. It also explains one of the reasons why professionals prefer larger SLR cameras over smaller compact cameras; another is you can change the lenses. Bottom line: If you already have a compact camera, disable the digital zooom and move in closer to your subject. If you are shopping for a camera, buy an SLR (aka D-SLR) with a full frame sensor. Avoid what is being called four-thirds, they use a smaller sensor that is not as sensitive to light and cannot produce sharp colorful images like a full frame sensor can.

in optical zoom zooming is manually