You know, to tell you honestly Bill, I'm not sure.
I do know I've read that normal maps are more powerful and versatile than bump maps. I do know that my own tests have proved that.
Then again, I never made my own bump maps (aside from procedural), and only started using normal maps when it became.... errmm... "normal" to do so in place of bump maps.

I won't say it is almost the same thing, considering the sheer popularity of normal maps and the number of pros who advocate them, but I also can't say (and prove) that they're better than bump maps either.

Maybe it's just a huge scam, far as I know, created by Pixologic and Autodesk.. but, when it comes to sculpting something in a sculpting app and exporting the textures and expecting to see in your rendering app what you see in your sculpting app, normal maps are at least far easier to deal with and to get results with. :-)