Heya Bob, welcome to ThePhotoForum.
Methinks you would need to read up something about photography and the basics on how a camera works under which circumstances to understand more about taking photographs in general.
What if we start to toss about words such as aperture, shutter speed, focal length etc about you and you haven't got a clue?
In very short: the lens has an opening, a little hole. And like our pupil in the eye can adapt to the light around us by dilating or becoming small, so can the lens (to certain extents, and depending on the model of camera you use).
When the "hole" (aperture) is wide open, it lets in a lot of light. The NUMBER shown is a SMALL one though. So WIDE open is SMALL number.
When the hole (aperture) is very small, the number is HIGH, and the amount of light let into the camera is - self-evidently - smaller.
When the aperture is wide, you can only get a small portion of the (naturally) 3-dimensional scene before you in focus. The rest will blur.
When the aperture is small, you can get a much larger portion of the (naturally) 3-dimensional scene before you in focus.
When the aperture is wide and there is a lot of light, the camera only needs a tiny amount of time to let in enough light to get a picture, so your shutter speed becomes VERY fast.
When the aperture is small and there is enough light, it still takes longer to bring about a well-exposed picture because fewer light can travel inside at one time.
Assuming you use your camera on AUTO-mode, it will adapt to all light situations all by itself. Which means as soon as there is not too much light, it will a) go wide open (decrease the range where things appear sharp, i.e. are in focus), and - if necessary - b) use long shutter speeds which make handholding a photo impossible.
So you will either get blurriness from out of focus things, or from camera shake.
With many compact cameras such as the Powershots, you can only get as close as about 70 cms to an object to still get a sharp picture. Anything closer is too close. But you can change the settings to so-called "macro" indicated by a flower symbol on the back of the camera. That will then open the lens wide and give you more range to take close-up. Without those settings, though, all close-ups will turn out blurry.
I think I have picked out SOME reasons why photos can become blurry now, haven't I? Hope it was a first help, and other than that ... well, Google is your friend ("aperture", "shutter speed") and books on photography are, too.