I am looking at tile on Lowes.com. I am wondering, what does surface type mean on the tile they have available ?

If you go to Lowes.com, search for "tile" in upper right search box, then click Floor Tile on left, in the column on the left under the prices is Surface Type

0.6 (4)

0.71 (1)

0.73 (33)

Semi-Vitreous (1)

Smooth (751)

Textured (168)

My aunt is considering a wet room. She will be tiling the entire floor of the bath and the walls (do you tile ceiling?). What are recommendations for floor tile so it is not too slippery ? When I choose "textured" as surface type, some of the tiles it returns says Smooth in the description. For example, http://www.lowes.com/pd_188333-50101-L30193_4294856525__?productId=1159219