A RAW image file is huge, and can't be moved around very well. Most high end photo editing tools have additional functions that you can use if your file is in the RAW format, like lens corrections. In the olden days (like 5 years ago) cameras did not have the processing horsepower to do these things, so professional photographers (who are the only ones who care) shot all thier photos and saved them in RAW format, so they could use thier computers to do the heavy lifting.
These days, high end camers have the horsepower to apply lens corrections, color corrections, etc, then convert the file into a lossless JPEG. You have to set the camera correctly, or you will get a compressed JPEG with losses. Pisnum is correct in saying RAW is for professionals only. If you are not going to apply diffraction corrections, or change the focus of different parts of your photo after you take the picture, you will be happier with a JPEG.