I had an interview with a woman who just spent close to two weeks, working a couple of hours a day, culling and editing 649 vacation photos. They are all digital and she uses Photoshop Elements, a more compact version of Photoshop.
I asked her what was the most common thing she did to the pictures before putting them on Facebook and sending links to them out to friends by email. Her most used tool is cropping. The first need is to make the whole picture file smaller. From her camera or iPad, a picture may
be in quite a large format.
This 2nd shot of the salad is only .7 mb, about half the picture information of the one above and seems like a close-up of the important parts of the picture.
That is the sort of cropping and focusing (and eliminating some parts of the picture) that she does by the hour. The software allows her to brighten or darken a picture, to increase its contrast and make other changes. 
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