The Zeiss website can explain the difference between the Planar and Sonnar lenses better than I can.

As far as autofocus, it depends on what camera you have. If you have a Contax 645, or N 35mm or G series camera then yes. If you have a Hasselblad or Contax Aria or RTS then no. Rollei, I'm not sure about, most of the Zeiss lenses for Rollei are MF, but there might be a couple of Autofocus models available.