Ball Bearing Surfaces

Yes they touch. I don't think I understand your question though. Here are a couple of images to hopefully help you get it.

http://en.wikipedia.org/wiki/File:BallBearing.gif
http://en.wikipedia.org/wiki/File:Four-point-contact-bearing_din628_type-qj_180-ex.png

Realize that balls rather than regular roller bearings are used when thrust loads are needed to be taken. As such, they are typically (and most time need to be) loaded in one direction only.

 

There are two answers. In an ideal bearing, there is no sliding. In all real bearings, there is some sliding, but it is due to the deformation or angular mislaignment.