Digital cameras are wonderful, but often it's hard to tell how well you've focused until you download the photos to your computer. Also, due to the way digital sensors process information, most digital image data usually needs to be sharpened. Sharpening gives the impression of improved focus. Even film shots may look just fine in a 4 x 6-inch print, only to be revealed as not so crisp once you scan them and zoom in.
Fortunately, Elements includes some almost miraculous tools for sharpening your images. (It's pretty darned good at blurring them, too, if you want—see Section 126.96.36.199.)
Elements does include a Sharpen tool, but it turns out it's not the most useful solution available. That honor goes to the Unsharp Mask. Honorable mention goes to the High-Pass filter. All three are covered in the following sections.
Most of the time, the best way to sharpen an image is by using the sharpening filters. If you go to Filter → Sharpen, your choices are Sharpen, Sharpen Edges, Sharpen More, and something called Unsharp Mask. Although it sounds like the very last thing you'd want, the Unsharp Mask is actually by far the most capable and versatile of the sharpening tools, as well as having the most counter-intuitive name in all of Elements.
To be fair, it's not Adobe's fault. Unsharp Mask is an old darkroom term, and it actually does make sense if you know how they used to do it with film. Film developers would immediately know what to do with the Unsharp ...