why jpeg picture gets blurry when zoomed in? is there any software to make them clear?

There are a couple reasons for this. One, if you're using a point and shoot camera, the digital zoom feature will reduce the resolution of the image, making it more pixellated, and thus blurry. Stick with optical zoom only, and you won't have that problem.

Two, any zoom will reduce the amount of light that enters your camera, thus increasing the shutter speed beyond the range of handheld. All you need to do is mount your camera on a tripod to fix this.

Imaging software like Photoshop can sharpen images, up to a point. If they're just a little soft, it will help. But if they're really blurry to begin with, image sharpening won't help.

Well I'm going to assume that your talking about zooming in on the computer. The reason this is is because what your doing is getting closer to the pixels (colored squares that make the picture) Therefore, really the only solution that I can think of is getting a camera with more megapixels this will give you more pixels to zoom in on making it less blurry when zooming in. As of software, photoshop is good but for that price you can buy a new camera. :)

No, because the information you'd need to "fill in the blanks" isn't there. However, you CAN use filters to sharpen the image which may make it seem clearer even if you're not actually seeing anything new.

I could go on about it but I'm too lazy to type it all out so here's a site I know that has all the work done.

Its blurry cause there are less pixels in that area

I think there is.