Bathroom Tiling for Wet Room - What is behind tile

what do we need to put up on the walls and floor before we lay the tiles, we know we should use fibre cement on floor but what do we use on walls gib or ! thanks

I think tanalised ply is far superior for the floor. For the walls gib aqualine or a James Hardy villa board. Also need a waterprooofing membrane, bond breaking tape at wall/floor intersections. Fibreglass tape over all joins. I think you need to talk to a tile shop or professional tiler