Checkers Anyone?

I'm test-driving a new camera, my first DSLR.  The photo above, and the one below, were taken with the new camera.  

Why do I need, OK, want, a new camera?  What's wrong with the old one?  Well, there's nothing "wrong" with the old one, it takes great photos.  In spite of that, it's not a DSLR, and the intent all along was to use it as a learning tool before investing in something more expensive.  I caught a lucky break when a good friend of mine, who is also upgrading his equipment, offered to sell me his DSLR at a can't-say-no price.

I still haven't answered the question as to "why" I want a better camera.  That's a deep question, or more precisely, a depth question.  Without getting into f-stops and other photography jargon, I'll just ask you to look at this photo:

The image on the left is from the old camera, the one on the right from the new camera.  In both photos, the boxcar and the tracks are in focus.  Moving back to the two guys on the platform, they're a little out of focus in the left image, but still sharp in the right image.  Moving further back to the background trees, they're completely out of focus in the left image, but nicely focused in the right image.  This is called "depth of field", and my old camera has a very limited depth of field.  Unfortunately, taking good model photos requires a good depth of field, thus the desire for a better camera.