I believe that for indoor use there's little difference. Installation is the same and after it's installed, you can't tell one from another.
Generally, porcelain is a little more expensive, and a lot of ceramic is not rated for frost. But that's only a concern for outdoors.
I'd say choose what you like best and go for it.

No, but there is a differance between wall tile and floor tile.

Please help... would it not be smart to use 6 inch wall tiles for floor tiles in a bathroom? What is the difference between floor and wall tiles anyway.

Thanks!

Ceramic tile rated for wall use usually is not used on floors. The clay backing is softer and not meant to be weight bearing. Gouges can easily occur when things are dropped on them. Some tile that carry a wall rating can be used in residential floors but I never understood why it then carried a wall rating.

Bottom line, get something meant for the floor so you will avoid problems in the future.