What is the difference between aperturesize and shutter speed??????

Pretty basic and not hard to get hold of: the shutter speed refers to how long the camera shutter stays open to let in light. The aperture is the opening it lets the light through. So the bigger the aperture, the more light gets to the sensor (or film) and likewise, the slower the shutter setting, the more light gets to the sensor. Too much light=overexposure, and the picture looks washed out and pale. Not enough light=underexposure, and the picture looks dark and muddy. Cameras are set up so that doubling the shutter speed so that there is only 1/2 as much time for light to get in (say, from 1/50 to 1/100 sec) is the same as halving the aperture size, because the aperture is only big enough for 1/2 the ligh to get through in the same time. That means that halving the exposure and doubling the aperture keeps the exposure the same. Shutter speeds are set up so that each setting is half the one next to it in the sequenc e on the dial (or double if you go in the opposite direction). Same with aperture settings (called "f stops"): each one is half the size of the one next to it (or double), but there is a complication...the smaller the f-stop, the larger the aperture. If you were to think of the shutter speeds the same way, it is the same: a 500th is half the speed of 250th because they really mean 1/500 and 1/250. Same with f-stops: they really mean 1/2.8 and 1/4 (they are ratios - but don't sweat it). Your camera will figure out what it thinks is the best combination, but if you are not happy, you can over-ride the settings to give a better result. A good starting point is to remember that faster shutter speeds ca be used to freeze motion (think a water drop hitting the surface or a baseball leaving the bat), slower speeds to make moving objects blurred (those amazing shots of waterfalls and rapids where the water looks like milk). Smaller apertures (like f16 or f22) keep more of the picture looking sharp, which is good for views and landscapes, while you can use small apertures (like f2.8) to keep the subject sharp while the background is out of focus - great for portraits and macro shots. For moreinfo, see my articles on this subject at http://www.qassia.com/creative-shutter-control and http://www.qassia.com/creative-aperture-control

Aperture is how wide the shutter is open. Shutter speed is how long the shutter is open. The wider the shutter opens, the smaller the f number is. So an f/2 is going to be a very wide hole while an f/22 is going to be a very small hole. With a wide open shutter, you're going to get a more shallow depth of field. Your subject is going to be in focus, but the background is going to be blurred. This effect is mostly used when photographing flowers. If you're going to be photographing a landscape, you want all of the subject to be in focus. So you're going to want to use a very small aperture like f/22. As for shutter speed, the longer your shutter is open the more movement you are going to capture. When shooting in very dark conditions, you're going to need a longer shutter speed to be able to capture your subject. When shooting in very bright, light conditions, you are going to need a very short shutter speed so that your photos don't get over-exposed. When shooting with longer shutter speeds, it is always a good idea to use a tripod!

I started a discussion a while back about this and I got a few good answers from some good people here at myLot. Here's the link to the discussion: http://www.mylot.com/w/discussions/1692670.aspx They give a clear discussion of their differences and when to use them.