Donna,
The Canon 5D is a very high end camera used by many professionals. I got that camera and love it. I also have a number of professional lenses since that is my hobby.
The Canon Digital Rebel is the entry level DSLR.
If you are in the market for a good compact digital camera, the Canon s80 is a good choice. Many pros use that as their backup - it's brand new, 8 megapixels (very high) and has some nice automatic settings.