I did a post awhile back on why shooting in RAW allows you so much more editing flexibility. I won’t go into detail here, but I’ll post some examples of un-edited photos along with the finished version so you can see what a huge difference there is.
This is an example of a scene with extreme bright and dark areas, because I was shooting into the sun. I exposed mostly for the sky, so the trees are black in this straight-from-the-camera version. So I still have blue sky, but how much detail is in the black areas?
Some of the dark areas are still dark, because there IS a limit to the dynamic range of camera sensors. But now you can actually tell the trees are green, and there is more detail in the water. This is a huge advantage of using RAW files: you can darken light areas and bring out shadow detail and still have a photo that doesn’t look over-processed, pixelated, or burned.
Here is another example of a photo with some very dark areas, though the dynamic range is not so extreme because the sun has already set.
I may have over-done this one, just to illustrate what’s possible. You can barely see part of the log in the first photo, but none of the rocks that show up after adjustments. I’ve probably added a bit too much saturation in the colors, but point here is shadow detail. Look at the far shore in both photos. There are actually buildings over there that don’t even show in the un-edited version.
This photo was taken when the sun was still up, but just passing below the tree tops to the far left. So we have more overall light than the last example, but we still have dark areas with little detail. These lighting conditions fall in between the last two examples in terms of overall brightness.
The key is that the dark areas are still dark, but they have so much more visible detail than the unprocessed version! You can edit JPEG images in a similar way, but you cannot push them near as far without them starting to break up, and get noisy and pixelated.
What you need to edit RAW photos from your camera is, obviously, a camera that can take RAW images, and a RAW editor such as Lightroom, Adobe Camera RAW, or Apple Aperture. I actually learned a lot by watching YouTube videos and trying things out.