A correspondent on Flickr asked me why her photos taken with her Canon SX220 compact are pale and washed-out compared to mine taken with the same camera. This subject comes up a lot so I thought I'd copy and paste my answer for those of you relatively new to photography. Here's what I wrote:
"The simple answer is that the washed-out photo is straight out of the camera, whereas mine has had some post-processing. Let me explain:
The sensor (the part that records the picture) in even a modern camera can't detect as big a range of light and colour as the human eye can. If you were to take a photo, print it out at home, then take it back to the same location and hold it up, you'll see that compared to reality the photo will lack contrast - it will look washed out and the colours won't be as saturated. So a good photographer will, after copying his photos to a hard disk and backing them up, open them in a photo editing program to adjust for this. This is known as post--processing.
The most popular editing software is Photoshop CS, and it's very expensive, but it allows you to do a lot. You can not only bring back the contrast and colour to your photos, you can also create composite photos, for example, putting your subject onto a new background. Photoshop has a great many other functions, many of which aren't needed by the photographer.
The second most popular software is Lightroom and this is a lot less expensive but doesn't do as much; it's great at managing your photos and adjusting contrast and colour, and allows you to go further; for example, you can use an Adjustment brush to alter small areas of your picture, making them lighter or darker, sharper or blurrier, warmer or cooler, and so on. And it has a spot-healing tool to get rid of small unwanted objects such as sensor spots - caused by dust on the camera's sensor, as well as other features useful for the photographer.
There's also a cut-down version of Photoshop called Elements which does almost everything the average photographer might need to do. This is even cheaper than Lightroom and includes a photo management suite as well as the editor.
A free alternative to Photoshop is Gimp, which does a lot more than Elements, but fewer people use it which might mean that it takes longer to get help if you have a problem with it.
There are many other photo editing and post-processing programs, far too many for me to list. But there is one that I recommend to beginners. It's called Snapseed and you can get it for Windows, Mac, iPhone, iPad, and Android phones and tablets. It doesn't cost very much compared to the others and can do most of what beginners to photography might want to do. It's very easy to use and there are step-by-step video tutorials on the Snapseed website.
I hope I've explained well enough what the problem is and some possible solutions."
I should add the usual disclaimer that I have nothing to do with Nik Software (who produce Snapseed) as a company other than being a user and a big fan of their software.